UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of

the Securities Exchange Act of 1934 (Amendment No.    )

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

Byline Bancorp, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

Notice of Annual Meeting of Stockholders of Byline Bancorp, Inc.

A list of stockholders entitled to vote at the meeting will be available for inspection at the Company’s main office located at 180 North LaSalle Street, Suite 300, Chicago, Illinois 60601 for a period of ten days prior to the Annual Meeting and will also be made available virtually at the Annual Meeting itself for examination by any stockholder upon request.

We are taking advantage of the Securities and Exchange Commission’s rules that allow companies to furnish proxy materials to stockholders via the internet. We sent a notice of internet availability of proxy materials (the “Notice”) to holders of our common stock as of the record date on or about April 20, 2026. The Notice describes how you can access our proxy materials, including this proxy statement, beginning on April 20, 2026.

WHETHER OR NOT YOU EXPECT TO ATTEND THE ANNUAL MEETING, PLEASE SUBMIT YOUR PROXY
WITH VOTING INSTRUCTIONS. YOU MAY VOTE BY TELEPHONE, VIA THE INTERNET OR BY MAIL.

TABLE OF CONTENTS

PROXY STATEMENT
FOR THE 2026 ANNUAL MEETING OF STOCKHOLDERS
TO BE HELD ON JUNE 2, 2026

The enclosed proxy is solicited on behalf of the board of directors (the “Board of Directors” or the “Board”) of Byline Bancorp, Inc., a Delaware corporation (the “Company”, “Byline Bancorp” or “Byline”), which is a registered bank holding company that owns and operates Byline Bank (the “Bank”), for use at the 2026 Annual Meeting of Stockholders (the “Annual Meeting”) to be held virtually on June 2, 2026 at 8:30 a.m. Central Daylight Time. This proxy statement (this “Proxy Statement”), together with the Notice of Annual Meeting and proxy card, is first being made available to stockholders on or about April 20, 2026.

Unless we state otherwise or the context otherwise requires, references in this Proxy Statement to “Byline,” “we,” “our,” “us,” “ourselves,” “the company” and “the Company” refer to Byline Bancorp, Inc., and its consolidated subsidiaries.

Important Notice Regarding the Availability of Proxy Materials for the
Stockholder Meeting to be Held on June 2, 2026

Pursuant to the applicable rules of the Securities and Exchange Commission (the “SEC”), we have elected to provide access to our proxy materials via the internet. Accordingly, we sent a notice of internet availability of proxy materials to our stockholders. The Notice provides stockholders with instructions on how to access and review this Proxy Statement and our 2025 Annual Report online, as well as vote online. We, like many public companies, have determined that providing proxy materials electronically significantly reduces our printing and mailing costs associated with the distribution of printed copies of our proxy materials to our stockholders.

Stockholders who receive the Notice will not receive a printed copy of the proxy materials by mail unless you request one. All stockholders can access the proxy materials on the website referred to in the Notice or request to receive a printed set of them. Instructions on how to access the proxy materials via the Internet or to request printed copies may be found within the Notice. In addition, stockholders may request to receive proxy materials in printed form by mail or electronically by email on an ongoing basis.

YOUR VOTE IS IMPORTANT

Please vote via the Internet, Telephone or Mail.

Internet: www.proxyvote.com

Telephone: 1-800-690-6903 and follow the instructions

If you are voting by mailing your proxy card, please mark, sign and date the proxy card when received and return it promptly in the self-addressed, stamped envelope that we have provided.

About the Meeting

What is the date, time and place of the Annual Meeting?

Our 2026 Annual Meeting of Stockholders will be held on Tuesday, June 2, 2026, beginning at 8:30 a.m., Central Daylight Time, virtually at www.virtualshareholdermeeting.com/BY2026.

What is the purpose of the Annual Meeting?

At the Annual Meeting, stockholders will act upon the matters outlined in the Notice of Annual Meeting on the cover page of this Proxy Statement, consisting of:

Why did I receive a notice in the mail regarding the availability of proxy materials on the internet instead of a full set of proxy materials?

Pursuant to the applicable rules of the SEC, we have elected to provide access to our proxy materials via the internet. Accordingly, we sent a notice of internet availability of proxy materials to our stockholders. The Notice provides stockholders with instructions on how to access and review this Proxy Statement and our 2025 Annual Report online, as well as vote online. We, like many public companies, have determined that providing proxy materials electronically significantly reduces our printing and mailing costs associated with the distribution of printed copies of our proxy materials to our stockholders.

Stockholders who receive the Notice will not receive a printed copy of the proxy materials by mail unless you request one. All stockholders will have the ability to access the proxy materials on the website referred to in the Notice or request to receive a printed set of the proxy materials. Instructions on how to access the proxy materials via the internet or to request printed copies may be found within the Notice. In addition, stockholders may request to receive proxy materials in printed form by mail or electronically by email on an ongoing basis.

Who is entitled to vote at the Annual Meeting?

Only our stockholders of record at the close of business on April 8, 2026, the record date for the meeting, are entitled to receive notice of and to participate in the Annual Meeting. If you were a stockholder of record on that date, you will be entitled to vote all of the shares you held on that date at the meeting, or any postponement(s) or adjournment(s) of the meeting. As of the record date, there were 45,419,166 shares of common stock outstanding, all of which are entitled to be voted at the Annual Meeting. As of the record date, there were 47,849,290 shares of common stock issued.

A list of stockholders will be available at our offices at 180 North LaSalle Street, Suite 300, Chicago, Illinois 60601 for a period of ten days prior to the Annual Meeting and will also be made available virtually at the Annual Meeting itself for examination by any stockholder.

What are the voting rights of the holders of our common stock?

Holders of our common stock are entitled to one vote per share on each matter that is submitted to stockholders for approval. Stockholders do not have cumulative voting rights.

Who can attend the meeting?

All stockholders as of the record date, or their duly appointed proxies, may virtually attend the Annual Meeting.

What constitutes a quorum?

The presence at the meeting, in person (virtually) or by proxy, of the holders of a majority of the outstanding shares of common stock entitled to vote at the meeting as of the record date, will constitute a quorum, permitting the meeting to conduct its business. Proxies received but marked as abstentions will be included in the calculation of the number of shares considered to be present and entitled to vote at the meeting for purposes of determining a quorum. As of the record date, there were 45,419,166 shares of common stock outstanding, all of which are entitled to be voted at the Annual Meeting. If less than a majority of the outstanding shares of common stock is represented at the Annual Meeting, either the Chairperson of the meeting or holders of a majority of the shares so represented may adjourn the Annual Meeting from time to time without further notice.

What vote is required to approve each item?

The votes required to approve the matters to be presented at the Annual Meeting as listed in the Notice of the Annual Meeting are as follows:

Pursuant to our by-laws, broker non-votes will not be counted as shares entitled to vote on such matters and will have no effect on the outcome of such matters. Votes cast “for” or “against” and abstentions with respect to such matters will be counted as shares entitled to vote on such matters. A “broker non-vote” will occur when a nominee holding shares for a beneficial owner does not vote on a particular proposal because the nominee does not have discretionary power with respect to that proposal and has not received instructions from the beneficial owner. On matters other than the election of directors, abstentions will have the effect of a vote “against” such matters.

The inspector of election for the Annual Meeting will determine the number of shares of common stock represented at the meeting, the existence of a quorum, and the validity and effect of proxies, and shall count and tabulate ballots and votes and determine the results thereof.

Please note that if you hold your shares in “street name,” your bank, broker or other nominee will not be permitted to vote your shares on Proposals 1, 2, 3 or 4 absent specific instructions from you. Therefore, it is important that you follow the voting instructions on the form that you receive from your bank, broker, or other nominee.

What are the Board’s recommendations?

Our Board of Directors recommends:

Unless contrary instructions are indicated on your proxy, all shares represented by valid proxies received pursuant to this solicitation (and which have not been revoked in accordance with the procedures set forth below) will be voted:

How do I vote?

If you are a holder of record (that is, if your shares are registered in your own name with our transfer agent), you may vote using the proxy card contained in the proxy materials. Voting instructions are provided on the proxy card. The Notice also includes information about how to vote online (at www.proxyvote.com) or via telephone (1-800-690-6903).

If you are a street name holder (that is, if you hold your shares through a bank, broker, or other holder of record), you must provide your voting instructions in accordance with the voting instruction form provided by your bank, broker, or other holder of record, who will then vote your shares on your behalf. The availability of telephone or internet voting will depend upon your bank’s, broker’s, or other holder of record’s voting process.

If you attend the Annual Meeting virtually, you can vote your shares at that time.

Can I change my vote?

Yes. The giving of a proxy does not eliminate the right to vote at the Annual Meeting should any stockholder giving the proxy so desire. Stockholders have an unconditional right to revoke their proxy at any time prior to the exercise of that proxy, by (1) voting at the Annual Meeting, or (2) by filing a written revocation or duly executed proxy bearing a later date with our General Counsel & Corporate Secretary.

Who pays for costs relating to the proxy materials and Annual Meeting?

The costs of preparing, assembling, providing access to, printing and mailing this Proxy Statement, the Notice of Annual Meeting of Stockholders and the Annual Report and proxy card, along with the cost of posting the proxy materials on a website, are to be borne by us. In addition to the use of mail, our directors, officers, and employees may solicit proxies personally and by telephone, email, and other electronic means. They will receive no compensation in addition to their regular salaries for these efforts. We may request banks, brokers and other custodians, nominees, and fiduciaries to forward copies of the proxy materials to their principals and to request authority for the execution of proxies. We may reimburse these persons for their expenses in so doing, if applicable.

Stock Ownership

Security Ownership of Certain Beneficial Owners and Management

The following table shows information regarding the beneficial ownership of our common stock for the following:

Beneficial ownership is shown as of April 8, 2026, and is based on 45,419,166 shares of our common stock outstanding as of April 8, 2026. Beneficial ownership is determined in accordance with the rules of the SEC, which generally attribute beneficial ownership of securities to persons who possess sole or shared voting power or investment power with respect to such securities. A security holder also is deemed to be, as of any date, the beneficial owner of all securities that such security holder has the right to acquire within 60 days after such date, such as through the exercise of options or warrants or the conversion of a security. Except as otherwise indicated, all persons listed below have sole voting and investment power with respect to the shares beneficially owned by them. Except as otherwise indicated, the address for each stockholder listed below is c/o Byline Bancorp, Inc., 180 North LaSalle Street, Suite 300, Chicago, Illinois 60601.

* Represents beneficial ownership of less than 1%

** Also a Director of the Company

Delinquent Section 16(a) Reports

Section 16(a) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), requires our directors and executive officers, and persons owning more than 10% of a registered class of our equity securities, to file with the SEC reports of ownership and changes in ownership of the Company’s equity securities. These same persons are also required to furnish us with copies of all such forms. Based solely on a review of the copies of the forms furnished to us, we believe that, with respect to the 2025 fiscal year, all required Section 16(a) filings were timely made, with the exception of the following:

The table below sets forth information regarding each nominee for director. Currently, each of our directors is elected annually to serve a one-year term.

Information Regarding Nominees for Election

Roberto R. Herencia

Phillip R. Cabrera

Antonio del Valle Perochena

Mary Jo S. Herseth

Margarita Hugues Vélez

Steven P. Kent

William G. Kistner

Alberto J. Paracchini

Pamela C. Stewart

Carlos Ruiz Sacristán

THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS A VOTE “FOR” THE ELECTION OF EACH NOMINEE FOR DIRECTOR UNDER PROPOSAL 1.

Corporate Governance

Composition of Our Board of Directors

Our Board of Directors currently has ten members. Under our Amended and Restated Certificate of Incorporation and By-Laws, the number of directors constituting our Board of Directors is fixed from time to time by resolution of the Board of Directors. The Board met six times during 2025.

Board Leadership Structure and Qualifications

We believe that our directors should have the highest professional and personal ethics and values, consistent with our longstanding values and standards. They should have broad experience at the policy making level in business, government, or banking. They should be committed to enhancing stockholder value and should have sufficient time to carry out their duties and to provide insight and practical wisdom based on experience. Each director must represent the interests of all stockholders.

When considering potential director candidates, our Board of Directors considers the candidate’s character, judgment, diversity, skills, including financial literacy, and experience in the context of our needs and those of the Board of Directors. Our Board also considers the candidate’s service on boards of other companies and whether such service would impair the candidate’s ability to perform responsibly all director duties for Byline.

Our Board of Directors does not have a formal policy requiring the separation of the roles of Chief Executive Officer and Chairman of the Board. It is the Board of Directors’ view that rather than having a rigid policy, the Board of Directors, with the advice and assistance of the Governance and Nominating Committee, and upon consideration of all relevant factors and circumstances, will determine, as and when appropriate, whether the two offices should be separate. Currently, Mr. Herencia holds the combined positions of Executive Chairman of the Board and Chief Executive Officer, while Mr. Paracchini is President of the Company, as well as President and Chief Executive Officer of Byline Bank. Also, Mr. del Valle Perochena has been the Lead Director of the Company since February 2021. We believe this current structure provides the appropriate level of oversight and management, and supports the execution of the Company’s strategic plan, specifically its growth strategy, as a leading commercial bank in the Chicago Metropolitan Area.

Board Diversity

Our Board believes that a range of experience, knowledge, and judgment, as well as a diversity of perspectives, experience, geographic regions, gender, race, and national origin on the Board, enhances the overall effectiveness of the Board. At present, the overall diversity of our Board is 70%. Gender diversity accounts for 30% of the overall diversity, and race or ethnic diversity accounts for 60% of the overall diversity.

Director Independence

Under the rules of the New York Stock Exchange (“NYSE”), independent directors must comprise a majority of our Board of Directors. The rules of the NYSE, as well as those of the SEC, impose several requirements with respect to the independence of our directors. Our Board of Directors has undertaken a review of the independence of each director in accordance with these rules. Based on information provided by each director concerning his or her background, employment and affiliations, our Board of Directors has determined that each of Phillip R. Cabrera, Antonio del Valle Perochena, Mary Jo S. Herseth, Margarita Hugues Vélez, Steven P. Kent, William G. Kistner, Pamela C. Stewart and Carlos Ruiz Sacristán do not have relationships that would interfere with the exercise of their independent judgment in carrying out the responsibilities of a director and that each of these directors is “independent” as that term is defined under the applicable director independence rules. Our Board of Directors has determined that Messrs. del Valle Perochena, Cabrera and Kent also satisfy the heightened independence requirements for Compensation Committee members, and that Messrs. Kistner, Cabrera, Kent and Ms. Hugues Vélez also qualify as independent directors under the heightened independence requirements of Rule 10A-3 of the Exchange Act for members of the Audit Committee. In making these determinations, our Board of Directors considered the current and prior relationships that each non-employee director has with our company and certain other facts and circumstances our Board of Directors deemed relevant in determining their independence, including the beneficial ownership of our capital stock by each non-employee director.

In May 2025, in response to the 2025 proxy report issued by Glass Lewis, the Company submitted information to Glass Lewis which specifically addressed the independence of Mr. del Valle Perochena under the rules of the

NYSE and the annual analysis and assessment conducted by the Board in evaluating director independence, as more particularly described below.

Each year the Board analyzes the independence of each of the Company’s directors, including Mr. del Valle Perochena, in detail. As general partner of MBG Investors I, L.P., Mr. del Valle Perochena possesses sole voting and investment power with respect to the shares held by MBG Investors I, L.P. and may be deemed the beneficial owner of such shares equivalent to 26.14% of the Company as of April 8, 2026. After analyzing the factors specific to Mr. del Valle Perochena, the Board determined that he does not have any relationship to the Company which is material to the director’s ability to be independent from management in connection with the duties of a Lead Director, the chair of the Compensation Committee, or the chair of the Governance and Nominating Committee. Further, through the Foreign National Commitments that Mr. del Valle Perochena entered into with the Board of Governors of the Federal Reserve System (the “Federal Reserve”), described in detail in the “Foreign National Commitment” section of this Proxy Statement, there are strict limitations applicable to him, and the companies controlled by him, with respect to entering into transactions with the Company and Byline Bank. The Board believes that these limitations support its determination that Mr. del Valle Perochena is independent under the rules of the NYSE. We also considered the applicable provisions of the NYSE Listed Company Manual as it relates to determining director independence, in which the NYSE expressly states that it does not view ownership of even a significant amount of stock, by itself, as a bar to a finding of independence.

Glass Lewis had raised a similar issue with respect to Mr. del Valle Perochena’s independence in its 2023 and 2024 proxy reports regarding the Company. In response to the 2024 report, the Company submitted to Glass Lewis information that specifically addressed the independence of Mr. del Valle Perochena under the listing rules of the NYSE and the annual analysis and assessment conducted by the Board in evaluating director independence, including the independence of Mr. del Valle Perochena. In response to the 2023 report, Mr. Herencia, the members of the Board’s Governance and Nominating Committee and the Company’s Chief Human Resources Officer met with representatives of Glass Lewis to discuss Glass Lewis’ concerns and to provide the Company’s perspective regarding Mr. del Valle Perochena’s independence, which perspective is provided in the immediately preceding paragraph. As a result of those discussions, we enhanced our disclosures in our 2024 and 2025 Proxy Statements regarding director independence and board governance, including the fact that each of the Board Committees are structured specifically to have a majority of independent members, and that the Board and the Committees hold executive sessions, where there is an opportunity for independent directors to discuss any necessary topics.

Director Term; Term Limits and Retirement Age

At present, Directors of the Company are elected annually to serve a one-year term, or until his or her successor is elected and qualified. At this time, we do not believe that we should establish term limits for directors as we aim to preserve and continue the contributions of our Directors who have developed insight into and historical knowledge and perspective with respect to the Company and its business over a period of time and who continue to provide significant and meaningful oversight and guidance to Company management.

Our Company's Corporate Governance Guidelines currently provide that no person may be nominated for election to the Company's Board if he or she has attained or will attain the age of 72 before the election. Our Corporate Governance Guidelines also provide that the Board may, in its discretion, waive this provision based upon a nominee's particular circumstances.

The following Company Directors are age 72 or older:

Our Board, upon the recommendation of the Governance and Nominating Committee, and in utilizing its discretion as provided for in our Corporate Governance Guidelines, has determined that at this time it is in the best interests

of the Company and our stockholders to waive the director retirement age provision for these Directors for the following reasons:

1. With respect to Mr. Cabrera, the Board believes that his continued service is essential in light of his extensive experience in corporate finance and treasury matters, including capital and liquidity management, as well as overall risk management, combined with his continued active and valuable contributions to the Board and its Committees.

2. With respect to Mr. Kent, the Board believes that his continued service is essential in light of his extensive experience in the financial services industry, including strategic planning, mergers and acquisition and integration, capital management and overall risk management, combined with his continued active and valuable contributions to the Board and its Committees.

3. With respect to Mr. Kistner, the Board believes that his continued service is essential in light of his extensive experience in audit and tax matters, corporate finance, oversight of internal and external audit functions and controls, and overall risk management, combined with his continued active and valuable contributions to the Board and its Committees.

4. With respect to Mr. Ruiz Sacristán, the Board believes that his continued service is essential in light of his extensive experience in executive management, strategic planning, corporate and overall risk management, combined with his continued active and valuable contributions to the Board and its Committees.

The Board and the Governance and Nominating Committee will continue to evaluate and assess the director retirement age provision contained within our Corporate Governance Guidelines annually in relation to the best interests of the Company and our stockholders.

Committees of Our Board of Directors

The standing committees of our Board of Directors consist of an Audit Committee, a Compensation Committee, a Governance and Nominating Committee and a Risk Committee. The responsibilities of these committees are described below. Our Board of Directors may also establish such other committees as it deems appropriate, in accordance with applicable law and regulations and our corporate governance documents. The following table summarizes the current membership of each of the committees of the Board of Directors.

● Member ○ Chair

Audit Committee

The Audit Committee assists the Board of Directors in fulfilling its responsibilities for general oversight of the integrity of our financial statements, our compliance with legal and regulatory requirements, the independent auditors’ qualifications and independence, the performance of our internal audit function and independent auditors, and risk assessment and risk management.

The Audit Committee works closely with management and our independent auditors. The Audit Committee has the authority to obtain advice and assistance from, and receive appropriate funding to engage outside legal, accounting or other advisors as the Audit Committee deems necessary to carry out its duties. The Audit Committee has adopted a written charter that among other things, specifies the scope of its rights and responsibilities. A copy of the Committee’s charter is available on our website at www.bylinebancorp.com under the “Corporate Governance Documents” tab.

The Audit Committee is comprised solely of members who satisfy the applicable independence, financial literacy and other requirements of the NYSE for audit committees, and at least one of its members is an “audit committee financial expert” as defined by the rules of the SEC, which is Mr. Kistner. Messrs. Kistner, Cabrera, Kent and Ms. Hugues Vélez also meet the heightened independence requirements of Rule 10A-3 of the Exchange Act.

Compensation Committee

The Compensation Committee sets and administers the policies that govern our executive compensation programs and is responsible for discharging the Board’s responsibilities relating to compensation of our executive officers and directors.

Under the Compensation Committee’s charter, the Compensation Committee may, at its discretion, delegate all or a portion of its duties and responsibilities to a subcommittee of the Compensation Committee. In addition, it may delegate authority to the Executive Chairman and Chief Executive Officer to approve compensation applicable to non-executive level Company employees, provided that the Compensation Committee reviews and approves the Company’s compensation structures applicable to non-executive level employees on an annual basis.

In 2025, the Compensation Committee retained Pearl Meyer & Partners, LLC (“Pearl Meyer”) primarily to assist the Compensation Committee in determining and structuring executive compensation and to assess the market competitiveness of the Company’s executive compensation program. The Compensation Committee has annually engaged Pearl Meyer for these and related services since 2014. With respect to any advice provided to the Committee by Pearl Meyer, the Compensation Committee received a letter from Pearl Meyer addressing factors relevant to SEC and NYSE rules regarding independence and conflicts of interest. After considering the information provided by Pearl Meyer and other factors, no conflicts of interest with respect to Pearl Meyer were identified by the Compensation Committee, and the Compensation Committee concluded that Pearl Meyer was an independent consultant.

The Compensation Committee has adopted a written charter that, among other things, specifies the scope of its rights and responsibilities. A copy of the Committee’s charter is available on our website at www.bylinebancorp.com under the “Corporate Governance Documents” tab. The Compensation Committee is comprised solely of members who satisfy the applicable independence requirements of the NYSE as they apply to members of compensation committees.

Governance and Nominating Committee

The Governance and Nominating Committee is responsible for making recommendations to our Board of Directors regarding candidates for directorships and the size and composition of our Board of Directors. In addition, the Governance and Nominating Committee is responsible for overseeing our corporate governance guidelines and reporting and making recommendations to our Board of Directors concerning governance matters.

The Governance and Nominating Committee has adopted a written charter that among other things specifies the scope of its rights and responsibilities. A copy of the Committee’s charter, as well as a copy of the corporate governance guidelines is available on our website at www.bylinebancorp.com under the “Corporate Governance Documents” tab. The Governance and Nominating Committee is comprised solely of members who satisfy the applicable independence requirements of the NYSE for governance and nominating committees.

Risk Committee

The Risk Committee is responsible for overseeing our enterprise risk management policies, commensurate with our capital structure, risk profile, complexity, size and other risk related factors.

The Risk Committee has adopted a written charter that specifies, among other things, the scope of its rights and responsibilities. A copy of the Committee’s charter is available on our website at www.bylinebancorp.com under “Corporate Governance Documents” tab.

In addition to the committees described above, the Board of Directors of Byline Bank also has an Executive Credit Committee, a Trust Committee, and an ALCO Committee. The Executive Credit Committee provides oversight of our credit risk management function. This Committee oversees the risk appetite, the development of policies, practices and systems for measuring credit risk and monitors the performance and quality of our credit portfolio. Ms. Herseth is Chairperson of the Executive Credit Committee, and the Committee’s other members include Messrs. Herencia, Paracchini, Kent, Cabrera and Ms. Stewart. The Trust Committee provides oversight in implementing policies for the Bank’s Wealth Management and Trust department, as well as practices and controls sufficient to promote high quality fiduciary administration. Mr. Kent is the Chairman of the Trust Committee, and the Committee’s other members include Messrs. Cabrera, Herencia and Ms. Herseth. The ALCO Committee provides oversight of the Asset and Liability Management function. Mr. Cabrera is the Chairman of the ALCO Committee, and the Committee’s other members include Messrs. Herencia, Kent, Paracchini and Ms. Herseth.

Board Oversight of Risk Management

Our Board of Directors believes that effective risk management and control processes are critical to our safety and soundness, our ability to predict and manage the challenges that we face and, ultimately, our long-term corporate success. Our Board of Directors, both directly and through its committees, including the Risk Committee, is responsible for overseeing our risk management processes, with each of the committees of our Board of Directors assuming a different and important role in overseeing the management of the risks we face.

The Risk Committee of our Board of Directors oversees our enterprise-wide risk management framework, which establishes our overall risk appetite and risk management strategy and enables our management to understand, manage and report on the risks we face, including our asset-liability, interest rate, liquidity, data privacy/cyber security, and information security and technology (including artificial intelligence) risks, among other types of risks. Our Risk Committee also reviews and oversees policies and practices established by management to identify, assess, measure and manage key risks we face, including the risk appetite metrics developed by management and approved by our Board of Directors. The Audit Committee of our Board of Directors is responsible for overseeing risks associated with financial matters (particularly financial reporting, accounting practices and policies, disclosure controls and procedures and internal control over financial reporting) and engaging as appropriate with our Risk Committee to assess our enterprise-wide risk framework. The Compensation Committee of our Board of Directors has primary responsibility for risks and exposures associated with our compensation

policies, plans and practices, regarding both executive compensation and the general compensation structure. Our Compensation Committee, in conjunction with our Chief Executive Officer, President, Chief Human Resources Officer and other members of our management as appropriate, reviews our incentive compensation arrangements to ensure these programs are consistent with applicable laws and regulations, including safety and soundness requirements, and do not encourage imprudent or excessive risk taking by our employees. The Governance and Nominating Committee of our Board of Directors oversees risks associated with the independence of our Board of Directors and potential conflicts of interest.

Our senior management is responsible for implementing and reporting to our Board of Directors regarding our risk management processes, by assessing and managing the risks we face, including strategic, operational, regulatory, investment and execution risks, on a day-to-day basis. Our senior management is also responsible for creating and recommending to our Board of Directors for approval appropriate risk appetite metrics reflecting the aggregate levels and types of risk we are willing to accept in connection with the operation of our business and pursuit of our business objectives.

The role of our Board of Directors in our risk oversight is consistent with our leadership structure, with our Chief Executive Officer, President, Chief Financial Officer, Chief Risk Officer, Chief Accounting Officer, General Counsel & Corporate Secretary, and the other members of senior management having responsibility for assessing and managing our risk exposure, and our Board of Directors and its committees providing oversight in connection with those efforts. We believe this division of risk management responsibilities presents a consistent, systemic and effective approach for identifying, managing and mitigating risks throughout our operations.

Stockholder Engagement and Communicating with Our Board

We believe in proactive and transparent communication and engagement with our stockholders to promote an understanding of the values we maintain, our governance framework, the decisions we make and how we make them, our business strategy and our financial performance, and we welcome receiving communications from our stockholders regarding these matters. Generally, our Chief Executive Officer and other executive officers interact with stockholders, and management is generally responsible for managing our corporate communications and investor relations activities. Throughout the year, our Chief Executive Officer, President and Chief Financial Officer regularly interact with significant stockholders regarding our performance, business strategy and other corporate matters. Our non-executive directors may speak or meet with stockholders as may be appropriate from time to time.

Stockholders may contact the Board, or any committee of the Board about matters specific to the Board’s and/or its committees’ oversight responsibilities. Written correspondence may be directed to the Board of Directors at Byline Bancorp, Inc., Attention: General Counsel & Corporate Secretary, 180 North LaSalle Street, Suite 300, Chicago, Illinois 60601. Inquiries from stockholders directed to the Board will be received and processed by the General Counsel & Corporate Secretary before being forwarded to the Board, the appropriate Committee or a particular director as designated in the communication.

Director Attendance at Our Annual Meeting and Board Meetings

Our Board expects each director to attend, either in person or remotely via conference call, the Company’s Annual Meeting of Stockholders each year, absent extenuating circumstances. All our directors serving on the Board in 2025 at that time attended our 2025 annual meeting. We currently anticipate that all our directors will attend the Annual Meeting. During 2025, each of our directors attended at least 90% of the meetings of the Board and Board committees on which they served.

Nominee Recommendations by Stockholders

Stockholders wishing to recommend persons for consideration by the Governance and Nominating Committee as nominees for election to the Board of Directors can do so by writing to the Governance and Nominating Committee at Byline Bancorp, Inc., Attention: General Counsel & Corporate Secretary, 180 North LaSalle Street, Suite 300, Chicago, Illinois 60601. Recommendations must include the proposed nominee’s name, biographical data and qualifications as well as a written statement from the proposed nominee consenting to be named as a nominee and, if nominated and elected, to serve as a director. If all necessary information is provided, the Governance and Nominating Committee will then consider the candidate and the candidate’s qualifications in the same manner as prospective nominees that are identified by the Committee. The Governance and Nominating Committee may contact the stockholder making the nomination to discuss the candidate’s qualifications and the reasons for it.

Any stockholder seeking to nominate persons for election to our Board of Directors must comply with our procedures for stockholder nominations described under the heading “Stockholder Proposals.”

Compensation Committee Interlocks and Insider Participation

None of the members of our Compensation Committee is currently or was previously an officer or employee of Byline or Byline Bank. In addition, none of our executive officers serves or has served as a member of the board of directors, Compensation Committee or other board committee performing equivalent functions of any company or other entity that has one or more executive officers serving as one of our directors or on our Compensation Committee.

Insider Trading Policies and Procedures

Our Board of Directors has adopted an insider trading policy (the “Insider Trading Policy”) governing the purchase, sale or other disposition of our securities by our Directors, officers and employees that we believe is reasonably designed to promote compliance with insider trading laws, rules and regulations, and any applicable NYSE listing standards. While not specifically covered by the Insider Trading Policy, it is our policy to comply with insider trading laws, rules and regulations, and any applicable NYSE listing standards, when engaging in transactions in Byline securities. A copy of the Insider Trading Policy is filed as Exhibit 19.1 to our 2025 Annual Report on Form 10-K and is also available on our website at www.bylinebancorp.com under the “Corporate Governance” tab.

Code of Business Conduct and Ethics

Our Board of Directors has adopted a code of business conduct and ethics (the “Code of Ethics”) that applies to all of our directors, officers, and employees, including our principal executive officer, principal financial officer and principal accounting officer and persons performing similar functions. Our Board has also adopted a Code of Ethics for Financial Officers. A copy of each code is available, without charge, upon written request to General Counsel & Corporate Secretary, Byline Bancorp, Inc., 180 North LaSalle Street, Suite 300, Chicago, Illinois 60601 and on our website at www.bylinebancorp.com under the “Corporate Governance Documents” tab. If we amend or grant any waiver from a provision of our Code of Ethics that applies to our executive officers, we will publicly disclose such amendment or waiver on our website and as required by applicable law, including by filing a Current Report on Form 8-K.

Director Compensation

Byline Bancorp, Inc. Director Compensation Program

Our director compensation program provides that each non-employee director receives an annual cash retainer of $115,000 for their service as a member of our Board of Directors, a portion of which may be paid in shares of restricted common stock at the director’s election. In addition, committee members and committee chairpersons receive the following additional cash retainers:

Under our director compensation plan, the annual cash retainer fees for directors, committee chairs and committee members are paid in twelve (12) equal monthly installments on the last day of each month, and newly appointed directors will be paid on a pro rata basis in relation to the time served. Directors may elect to receive up to 100% of the dollar amount of the annual board retainer in shares of our common stock to be issued pursuant to the Byline Bancorp, Inc. 2017 Omnibus Incentive Compensation Plan.

We also reimburse all directors for reasonable and substantiated out-of-pocket expenses incurred in connection with the performance of their duties as directors. We provide insurance policies for directors and officers and will indemnify directors to the fullest extent provided under Byline’s Certificate of Incorporation and By-laws as in effect from time to time.

Directors agree, in connection with their service as directors, that they will not, without the prior consent of Byline, directly or indirectly, provide any material services to any other banking entity which competes in any material respect with Byline and its subsidiaries as long as they serve as a director of Byline (other than services disclosed in writing).

Notwithstanding the above, any director who is also an officer of Byline shall not receive any additional compensation for serving in such capacity.

In October 2025, after receiving and considering market data and input from Pearl Meyer, the Compensation Committee's independent compensation consultant, the Compensation Committee recommended an increase to the annual cash retainer to be paid to non-employee directors to $130,000, as well as an increase in the annual cash retainer paid to the Lead Director (to $40,000).These changes will impact compensation paid to non-employee directors beginning June 2026.

2025 Director Compensation

The following table lists the individuals who served on our Board of Directors in 2025 and the compensation received for their service as directors in 2025, other than with respect to Mr. Herencia, our Executive Chairman and Chief Executive Officer, and Mr. Paracchini, our President, whose compensation as officers of the Company is detailed in the Summary Compensation Table in the “Executive Compensation” section of this Proxy Statement. All compensation paid to directors is for their service to both the Byline Board of Directors and the Byline Bank Board of Directors.

Director Stock Ownership and Retention Policies

In an effort to align the financial interests of our directors with those of our stockholders and to promote our long-term business objectives, non-employee directors are subject to certain stock ownership and retention requirements pursuant to the policy established by our Board and administered by the Compensation Committee.

Under the stock ownership policy, our non-employee directors are expected to accumulate shares of our common stock to meet the applicable ownership level within five years of their election or appointment. It is expected that they will acquire the required ownership level by retaining ownership of their equity compensation from the Company. Until the required level is achieved, the individual must retain at least 50% of his or her vested full value shares received as equity compensation.

Our non-employee directors are required to own a minimum number of shares of our common stock with an aggregate value equal to three times the amount of the Board retainer under our director compensation program.

Human Capital, Governance and Community Engagement

At Byline, we are a bank that believes in putting our name behind everything we do and we’re here to roll up our sleeves and help our customers write their stories. Our #1 core value, reflected in our “Things That Matter,” is our People, all of whom are encouraged to live out a shared purpose of making people’s lives better, helping businesses thrive, and strengthening the communities we serve. We believe purpose driven leadership facilitates progress in achieving a dynamic and inclusive workforce and in driving performance. We are dedicated to attracting, retaining, and developing top talent to accomplish our long-term strategy which is critical to our success.

As of December 31, 2025, we had 1,027 employees (1,018 full time, and 9 part time) in locations primarily across the Chicagoland and greater Milwaukee, Wisconsin areas.

Governance and Oversight

Our Board of Directors and executive management team are committed to executing on our long-term vision. Our Board members are accomplished leaders from diverse backgrounds, bringing the perspectives, skills, and experience necessary to use independent judgment that will effectively challenge and drive continued success. Our Board members oversee our corporate strategy and set the tone for our culture, values and high ethical standards, and, through its Committees, holds management accountable for results. The Compensation Committee reviews and monitors matters related to human capital management, including compensation and benefits, Company culture, talent development, employee engagement and other environmental, social and governance programs and initiatives.

Total Rewards

At Byline Bank we recognize that our most valuable resource is our People. We strive to become an employer of choice and many of our advantages are found in our four Total Rewards pillars: Pay; Benefits, Health and Wellness; Work-Life Harmony; and Professional Development.

Pay

We believe our compensation strategy supports our core principles and provides every employee with a competitive compensation package that fairly reflects their individual contributions to Byline. We offer a compensation package which includes base pay, short-term incentives (annual cash bonuses, commissions plans, and referral incentives) and long-term incentives (equity-based compensation) for applicable roles. Our approach seeks to ensure our compensation elements are competitive and market driven. In our commitment to transparency, our job architecture and paygrade structure is communicated to all employees.

Benefits, Health and Wellness

We believe that our benefits package not only attracts top talent but also fosters a positive and engaged workforce. We provide comprehensive health insurance plans, a 401(k) retirement savings plan with an employer match, and an Employee Stock Purchase Plan. Additionally, employees have access to resources and information to help with financial planning, mental health and well-being, and personal, family and life issues. We provide tuition reimbursement and a student loan repayment program. We offer wellness programs, an adoption and surrogacy assistance program, as well as coverage for fertility planning services within the healthcare plans, and provide up to 12 weeks of paid parental leave for employees. We have carefully designed the offerings to be progressive to meet the diverse needs of our workforce and that support their personal and professional lives. By investing in our employees, we seek to create an environment where everyone can thrive.

Work-Life Harmony

Eligible employees are provided generous paid time off and eleven paid federal holidays, and one floating Cultural Holiday to observe a holiday of personal significance.

Our work-life philosophy is to lead with flexibility. We offer our non-branch employees the opportunity to work either fully remote or hybrid based on the expectations of their role. We believe this level of flexibility to be a competitive advantage to attracting and retaining talent within and outside of our market.

Professional Development Opportunities

We recognize the critical importance of providing career development and advancement opportunities for all employees and we provide a variety of formal and informal development opportunities to help employees grow in their current roles and build new skills.

Management and Leadership skills are taught and practiced in a tiered series of formal development programs and reinforced by participants’ managers back in the workplace. Career Development Guides serve as a reference tool for learning opportunities specific to a current or desired career path. All employees have access to development resources for each of the five behavioral competencies expected of all Byline employees in the annual performance management process: Valuing Differences, Collaborating for Results, Delivering Customer Focused Solutions, Continuous Improvement, and Managing Risk. We believe one example of our success in developing our people is our ability to fill vacancies from within. During 2025, approximately 26% of our position postings were filled internally. We encourage our team members to pursue learning opportunities that will help improve performance and professional development.

Our Board of Directors oversees the succession planning for executive management on an annual basis. Key development is identified through formalized assessments for leadership, business, and executive role-based skills. Succession candidates create development plans that are monitored and updated on a quarterly basis.

Culture, Opportunity and Belonging

We seek to leverage our current workforce and prominent community outreach efforts to further enhance our engagement in four key areas:

Our employee resource groups (“ERGs”) were formed to support culture, opportunity and belonging across the organization, and are open to all employees. Overall diversity is measured as all females and males who are racially or ethnically diverse. Our diversity metrics for 2025 are as follows:

* Defined as gender and racial/ethnic diversity, as disclosed. Data as of December 31, 2025.

Community Engagement

We are committed to helping the local communities in which we live and work, grow and thrive, today and into the future. Throughout the year, employees make a positive impact in their local communities and have found a multitude of special ways to volunteer and give back. During 2025, Byline made and/or supported:

As of December 31, 2025.

Fair Employment Practices

Byline Bank is proud to be committed to maintaining a diverse workforce and an inclusive work environment. We are an Equal Opportunity / Affirmative Action employer. All qualified applicants will receive consideration for employment without regard to their actual or perceived race, color, religion, national origin, ancestry, marital or civil union status, sex, gender, pregnancy, age, citizenship status, disability, military or veteran status, gender identity, expression or preference, sexual orientation, genetic information, order of protection status or any other characteristic protected by law. We are committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. At Byline, our hiring decisions are based on merit, qualifications, and business needs.

Discrimination & Sexual Harassment in the Workplace

Byline Bank prohibits any form of unlawful discrimination, sexual harassment or other forms of harassment in the workplace. We believe that our employees should be able to work in an atmosphere free from all forms of harassment. Our policies regarding equal employment opportunity, discrimination, sexual harassment, and harassment are included in our Employee Handbook. All employees are required to review and acknowledge these policies in our Handbook annually. In addition, all employees are required to complete training regarding workplace discrimination, sexual harassment, and other forms of harassment annually.

Executive Compensation

The Company believes that its compensation policies and procedures, which are reviewed and approved by the Compensation Committee, encourage a culture of pay-for-performance and are strongly aligned with the long-term interests of stockholders. As more fully set forth under “Executive Compensation—Compensation Discussion & Analysis,” the Compensation Committee has taken a number of actions in recent years to further strengthen the Company’s compensation philosophy and objectives and the percentage of the compensation of senior executives which is “at risk.” As always, the Compensation Committee will continue to review all elements of the executive compensation program and take any steps it deems necessary to continue to fulfill the objectives of the program.

Stockholders are encouraged to carefully review the “Executive Compensation—Compensation Discussion & Analysis” section of this Proxy Statement for a detailed discussion of the Company’s executive compensation program. Because this stockholder vote is advisory, it will not be binding on the Board or the Compensation Committee. However, the Compensation Committee will take into account the outcome of the vote when considering future executive compensation arrangements.

The Board has authorized a stockholder vote on the compensation of the Company’s named executive officers as reflected in the Compensation Discussion & Analysis, including the disclosures regarding named executive officers compensation provided in the various tables included in this Proxy Statement, the accompanying narrative disclosures and the other compensation information provided in this Proxy Statement. This proposal, commonly known as a Say-on-Pay proposal, gives the Company’s stockholders the opportunity to endorse or not endorse the Company’s executive pay program and policies through the following resolution:

“Resolved, that the stockholders of Byline Bancorp, Inc. approve, on a non-binding advisory basis, the compensation of the named executive officers, as disclosed pursuant to the compensation disclosure rules of the Securities and Exchange Commission, including the Compensation Discussion and Analysis, the compensation tables and narrative discussion in this Proxy Statement for the 2026 Annual Meeting of Stockholders.”

Required Vote

The approval of, on an advisory (non-binding) basis, the compensation of the Company’s named executive officers as described in this Proxy Statement requires the affirmative vote of the holders of a majority of the shares present in person (virtually) or represented by proxy at the Annual Meeting and entitled to vote on the proposal. Abstentions will have the same effect as a vote against the proposal. Broker non-votes will not be counted as shares entitled to vote on the proposal.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR” THE APPROVAL OF, ON AN ADVISORY (NON-BINDING) BASIS, THE COMPENSATION OF THE COMPANY’S NAMED EXECUTIVE OFFICERS AS DESCRIBED IN THIS PROXY STATEMENT.

Overview

The Company’s 2026 Omnibus Incentive Compensation Plan (“2026 Omnibus Plan”) was adopted by the Board of Directors on April 7, 2026, subject to approval by stockholders. At the Annual Meeting, stockholders will be requested to approve the 2026 Omnibus Plan, which includes a reserve of 1,700,000 shares to allow for continued use of equity incentives. The purpose of the 2026 Omnibus Plan is to promote the long-term financial success of the Company and its subsidiaries by providing a means to attract, retain and reward individuals who can and do contribute to such successes, and to further align their interests with those of the Company’s stockholders.

The Company’s 2017 Omnibus Incentive Compensation Plan (the “2017 Omnibus Plan”) will expire in June 2027. Shares from the 2017 Omnibus Plan will not be available to grant under the 2026 Omnibus Plan. Upon approval of the 2026 Omnibus Plan, no additional awards will be granted under the 2017 Omnibus Plan, and all shares remaining for future issuance pursuant to the 2017 Omnibus Plan, which is estimated to be 165,903 as of April 8, 2026, will be canceled at that time. In addition, the maximum number of shares that may be issued under the 2026 Omnibus Plan will be reduced by one (1) share for every share subject to an award granted under the 2017 Omnibus Plan after April 8, 2026 and prior to the date the 2026 Omnibus Plan becomes effective. If our stockholders do not approve the 2026 Omnibus Plan, the 2017 Omnibus Plan will remain in effect in its current form.

How We Determined the Number of Shares to Request for the 2026 Omnibus Plan

In determining the number of shares needed for awards under the 2026 Omnibus Plan, we took into consideration our stock price, business performance, competitive pay-for-performance philosophy, regulatory requirements, historical experience, and expected use of equity-based awards in future years. The proposed additional 1,700,000 shares represent 3.7% of our outstanding common stock as of April 8, 2026.

In analyzing the proposed Plan, our Compensation Committee and Board of Directors engaged an independent compensation consultant, Pearl Meyer & Partners, LLC, to assist with recommending the number of shares that may

be issued under the Plan. In doing so, the Compensation Committee and the Board considered both our historical and expected burn rate and the resulting overhang as outlined below.

Burn Rate; Longevity of Authorized Shares. Burn rate (the measure of the annual rate at which companies use shares available for grant in their equity compensation plans), is an important factor for stockholders concerned about stockholder dilution. The burn rate is defined in terms of the gross number of equity awards granted during a calendar year divided by the weighted average number of shares of common stock outstanding during the year. We calculate our annual burn rate by adding the number of stock options granted plus the number of full value shares awarded and dividing the total by the number of weighted average common shares outstanding. Our burn rate for the fiscal years ended 2025, 2024, and 2023 was 0.78%, 0.90% and 0.77%, respectively. We believe our current three-year average burn rate of 0.81% should be viewed favorably by our stockholders. We do not anticipate that projected issuances of future awards under the Plan will vary materially from our historical awards and estimate that the additional 1,700,000 shares proposed to be authorized for issuance under the Plan will be sufficient for future grants for approximately five (5) years.

Overhang. Overhang is a measure that is sometimes used to assess the aggregate dilutive impact of equity programs such as the Plan. Overhang indicates the amount by which existing stockholder ownership would be diluted if the shares authorized for issuance under the 2026 Omnibus Plan, coupled with the shares subject to outstanding awards, were issued. As of April 8, 2026, the Company had outstanding equity awards of 17,669 stock options with a weighted average exercise price of  $12.70 and weighted average remaining term of 0.7 years, and 712,366 restricted stock awards outstanding, which, in aggregate, represents current dilution of approximately 1.6% (options plus restricted stock awards divided by shares outstanding) . The approval of the additional 1,700,000 shares to be authorized for issuance under the 2026 Omnibus Plan would result in overhang of approximately 5.4% relative to the approximately 45,419,166 shares outstanding as of April 8, 2026. We believe this level of overhang represents a reasonable amount of potential equity dilution and will allow us to continue granting equity awards.

Reasons to Approve the 2026 Omnibus Plan

The 2026 Omnibus Plan has been designed to build upon the effectiveness of the 2017 Omnibus Plan and incorporates the best governance practices to further align our equity-compensation program with the interests of our stockholders. The following is a list of some of the primary factors to be considered by stockholders in connection with approving the 2026 Omnibus Plan:

Governance Best Practices. The 2026 Omnibus Plan maintains features and practices from the 2017 Omnibus Plan that promote good governance and protect stockholders’ interests, including:

No “Liberal” Change in Control Definition. The change in control definition is not “liberal” and, for example, would not occur merely upon stockholder approval of a merger transaction. A change in control must actually occur in order for the change in control provisions in the plan to be triggered.

Double Trigger Change in Control Provisions. The change in control provisions under the 2026 Omnibus Plan do not provide for automatic acceleration of vesting of awards in the event of a change in control. Vesting of outstanding awards will occur if an employee experiences a termination of service without cause or for good reason on or within two years after the change in control.

No Tax Gross-Ups. No grantee is entitled to any tax gross-up payments for any excise tax pursuant to Sections 280G or 4999 of the Code that may be incurred in connection with awards under the 2026 Omnibus Plan.

No Liberal Share Recycling. Shares subject to an award under the 2026 Omnibus Plan will not be available for reuse if such shares are tendered in payment of a stock option exercise price, delivered or withheld to satisfy any tax withholding obligation, or covered by a stock appreciation right (SAR) (to the extent settled in shares) or other award. Additionally, shares that have been repurchased by the Company using stock option exercise proceeds are not added back to the share reserve.

No Dividend Payments on Unvested Awards. Requires that any dividends or dividend equivalent rights granted in connection with any type of award will be subject to the same vesting terms and conditions as the underlying award.

Clawback of Awards. All awards under the 2026 Omnibus Plan will be subject to any applicable law respecting recapture of compensation or such Company Compensation Clawback policy as may be in effect at the time of grant.

No Repricing or Cash Buyout of “Underwater” Awards. The exercise price of stock options and SARs may not be reduced, including through amendment, cancellation and exchange for another award or cash payment or other consideration, without approval of the Company’s stockholders.

No “Reload” Options or Stock Appreciation Rights. The plan does not permit the use of reload options or stock appreciation rights which provide that the exercise of a stock option or stock appreciation right can automatically trigger the grant of a new stock option or stock appreciation right.

No Transferability. Awards generally may not be transferred, except by the laws of descent and distribution.

No Evergreen Feature. The 2026 Omnibus Plan does not include an “evergreen” feature that would cause the number of authorized shares to automatically increase in future years.

Independent Oversight. The 2026 Omnibus Plan is administered by the Compensation Committee, which is comprised of independent members of our Board of Directors.

Cash Denominated Award Limit for Non-Employee Directors. Limits the maximum dollar value of awards that can be granted during any calendar year to any non-employee director, solely with respect to his or her service as a member of the Board.

Attract and Retain Talent. Approving the 2026 Omnibus Plan will enable us to continue to recruit, retain and motivate top talent at many levels within the Company necessary to our success. We grant equity-based awards to a broad spectrum of our employees, not only executives and named executive officers.

Modest Share Usage and Stockholder Dilution. When determining the number of shares authorized for issuance under the 2026 Omnibus Plan, our Compensation Committee and Board of Directors carefully considered the potential dilution to our current stockholders and projected future share usage needs for the Company to be able to make competitive awards to grantees as described above.

Summary of the 2026 Omnibus Plan

The following summary of the principal terms of the 2026 Omnibus Plan is qualified in its entirety by reference to the complete text of the 2026 Omnibus Plan, which is attached to this Proxy Statement as Annex 1. Capitalized terms used in this proposal that are not otherwise defined have the meanings given to them in the 2026 Omnibus Plan.

Purpose

The purpose of the 2026 Omnibus Plan is to help the Company: (1) attract, retain and motivate key employees (including prospective employees), consultants and non-employee directors; (2) align the interests of such persons with the Company’s stockholders; and (3) promote ownership of the Company’s equity.

Eligibility

Awards under the 2026 Omnibus Plan may be made to any employee, consultant or non-employee director of the Company. As of December 31, 2025, it is expected that approximately 185 employees, and all 8 of our non-employee directors as of December 31, 2025, will be eligible to participate in the 2026 Omnibus Plan.

Shares Available for Awards Under the 2026 Omnibus Plan

A total of 1,700,000 shares of our common stock may be issued under the 2026 Omnibus Plan, subject to adjustments by the Compensation Committee for stock splits and other events as set forth in the 2026 Omnibus Plan.

If an award granted under the 2026 Omnibus Plan expires, is forfeited or is settled in cash, the shares of our common stock not acquired pursuant to the award will again become available for subsequent issuance under the 2026 Omnibus Plan. Shares of our common stock subject to awards that are assumed, converted or substituted under the 2026 Omnibus Plan as a result of our acquisition of another company will not be counted against the number of shares that may be granted under the 2026 Omnibus Plan. With respect to awards of stock-settled SARs, the total number of shares that may be granted under the 2026 Omnibus Plan will be reduced by the full number of shares underlying the exercised portion of such award (rather than only the number of shares actually delivered upon exercise). The following types of shares under the 2026 Omnibus Plan will not again become available for the grant of new awards under the 2026 Omnibus Plan: (i) shares withheld to satisfy any tax withholding obligation, (ii) shares tendered to, or withheld by, us to pay the exercise price of an option and (iii) shares covered by a SAR (to the extent that it is settled in shares).

Administration of the 2026 Omnibus Plan

The 2026 Omnibus Plan will be administered by our Compensation Committee. The Compensation Committee has full authority to interpret the 2026 Omnibus Plan and award agreements, grant awards and determine the terms of such awards. The Compensation Committee can also delegate its authority as it deems appropriate in its sole discretion in accordance with applicable law.

Types of Awards

The types of awards that may be granted under the 2026 Omnibus Plan include:

Stock Options

Stock options may be granted as incentive stock options (within the meaning of Section 422 of the Internal Revenue Code of 1986 (the “Code”)) or nonstatutory stock options. A stock option entitles the grantee to purchase shares of our Common Stock at an exercise price that may never be less than the Fair Market Value of our Common Stock on the date the option is granted. No stock option can be exercised more than ten years after the date of grant. Dividend equivalent rights may not be granted in connection with any stock option.

Stock Appreciation Rights

Stock Appreciation Rights may be granted as the Compensation Committee may determine. No SAR can be exercised more than ten years after the date of grant. SARs entitle the grantee to receive a number of shares of our Common Stock, or cash, equal in value to the excess of the fair market value of our Common Stock over the exercise of the SAR, which may never be less than 100% of the Fair Market Value of our Common Stock on the date the SAR is granted. Dividend equivalent rights may not be granted in connection with any stock appreciation right.

Restricted Shares

Restricted shares are shares of our Common Stock that are subject to such terms and conditions as the Compensation Committee may determine. Upon the delivery of such shares, the grantee will have the rights of a stockholder with respect to the restricted shares, subject to any other restrictions and conditions as the Compensation Committee may include in the applicable award agreement. Restricted shares will, during the period of the restriction, have full voting rights. All ordinary cash dividends or other ordinary distributions paid upon any restricted shares will be retained by the Company and will be paid to the relevant grantee (without interest) when the award of restricted shares vests.

Restricted Stock Units

Restricted stock units are unfunded, unsecured rights to receive a share of our Common Stock or its equivalent in cash or other securities or property. A grantee of a restricted stock unit will have only the rights of a general unsecured creditor of the Company until delivery of shares, cash or other securities or property is made as specified in the applicable award agreement. On the delivery date specified in the award agreement, the grantee of each restricted stock unit not previously forfeited or terminated will receive one share of Common Stock, cash or other securities or property equal in value to a share of Common Stock or a combination thereof, as specified by the Compensation Committee. Restricted stock units may include the right to receive dividend equivalents provided that no dividend equivalents may be paid unless and until the restricted stock units vest.

Dividend Equivalent Rights

The Compensation Committee may grant dividend equivalent rights entitling a grantee to receive amounts equal to all or any portion of the regular cash dividends that would be paid on the shares covered by an award if such shares had been delivered pursuant to such award at the time of grant. The grantee will have only the rights of a general unsecured creditor of the Company until payment of such amounts is made as specified in the applicable award agreement. Dividend equivalents may not be paid unless and until the award to which they relate vests.

Other Stock-Based or Cash-Based Awards

Under the 2026 Omnibus Plan, the Compensation Committee may grant other types of equity-based, equity-related or cash-based awards subject to such terms and conditions that the Compensation Committee may determine. Such awards may include the grant or offer for sale of unrestricted shares of our common stock, performance share awards and performance units settled in cash.

Performance-Based Awards

Other Stock-Based or Cash-Based Awards may, at the discretion of the Compensation Committee, be granted subject to the achievement of performance goals or Performance Criteria for an applicable performance period, as determined by the Compensation Committee at the time of grant.

Change in Control

If employment or service relationship of a grantee (other than a non-employee director) with the Company is terminated by the Company without “cause” or by the grantee with “good reason” within two years after a “change in control” (as each term is defined in the 2026 Omnibus Plan), each award granted to such grantee prior to such change in control will become fully vested and, as applicable, exercisable. For a grantee who is a non-employee director, each award granted to such grantee prior to such change in control will become fully vested and, as applicable, exercisable upon a change in control. Any shares deliverable pursuant to restricted stock units will be delivered within 15 days following such termination of employment or service, or change in control for a non-employee director, unless the Compensation Committee determines otherwise, or as otherwise provided in the applicable award agreement. As of the change in control date, any outstanding performance-based awards shall be deemed earned at the greater of the target level and the actual performance level at the date of the change in control with respect to all open performance periods and will cease to be subject to any further performance conditions but will continue to be subject to time-based vesting following the change in control in accordance with the original performance period.

In general terms, except as expressly defined in an award agreement, a change in control under the 2026 Omnibus Plan means the first to occur of:

Nonassignability and No Hedging

Unless otherwise provided in an award agreement, awards granted under the 2026 Omnibus Plan may not be sold, exchanged, transferred, assigned, pledged, hypothecated or otherwise disposed of or hedged in any manner other than by will or by the laws of descent and distribution, and all such awards will be exercisable during the life of the grantee only by the grantee or the grantee’s legal representative. The Compensation Committee may permit a grantee to transfer any award to any person or entity the Compensation Committee so determines. All of the terms and conditions of the 2026 Omnibus Plan and the award agreements will be binding upon any permitted successors and assigns.

Repricing Prohibited

Reducing the exercise price of stock options or stock appreciation rights issued and outstanding under the 2026 Omnibus Plan, including through amendment, cancellation in exchange for the grant of a substitute award or repurchase for cash or other consideration (in each case that has the effect of reducing the exercise price), will require approval of the Company’s stockholders, except as otherwise permitted by the 2026 Omnibus Plan with respect to preventing the enlargement or dilution of rights. The Company will not grant any stock options or stock appreciation rights with automatic reload features.

Amendment

Our Board of Directors may amend, suspend, discontinue or revise the 2026 Omnibus Plan in any respect, provided that no such amendment may materially adversely impair the rights of a grantee of an award without the grantee’s consent. Unless otherwise determined by the Board, stockholder approval of any suspension, discontinuance, revision or amendment will be obtained only to the extent necessary to comply with any applicable laws, regulations or rules of a securities exchange or self-regulatory agency. If the Board determines it is appropriate for the 2026 Omnibus Plan to comply with the provisions of Section 422 of the Code, no amendment that would require stockholder approval under Section 422 of the Code will be effective without the approval of the Company’s stockholders.

Termination

Our Board of Directors may terminate the 2026 Omnibus Plan at any time. Unless terminated sooner by our Board of Directors, the 2026 Omnibus Plan will terminate on the day before the tenth anniversary of the date on which our stockholders approve the 2026 Omnibus Plan, and any outstanding award will remain in effect until such awards have been satisfied or terminated in accordance with the terms and provisions of the 2026 Omnibus Plan and the applicable award agreements.

Clawback

Awards under the 2026 Omnibus Plan will be subject to the terms of any clawback or recapture policy that the Company may adopt from time to time, and, in accordance with such policy, may be subject to the requirement that the awards be repaid to the Company after they have been distributed to the grantee.

Limits on Compensation to Non-Employee Directors

Aggregate awards to any one non-employee director in respect of any fiscal year, solely with respect to his or her service as a director, may not exceed $2,000,000 based on the aggregate value of cash awards and fair market value of stock-based awards, in each case, determined as of the date of grant.

U.S. Federal Income Tax Consequences of Awards Under the 2026 Omnibus Plan

The following discussion summarizes certain United States federal income tax consequences generally arising with respect to grants of awards under the 2026 Omnibus Plan under the law as in effect on the date of this Proxy Statement. This summary does not cover federal employment tax or other federal tax consequences associated with awards under the 2026 Omnibus Plan, nor does it address state or local tax consequences. Grantees who are granted awards under the 2026 Omnibus Plan should consult their own tax advisors to determine the tax consequences based on their particular circumstances.

Nonqualified Stock Options, Stock Appreciation Rights, Restricted Stock Units and Other Stock-Based Awards. A grantee generally is not required to recognize income upon the grant of a nonqualified stock option (“NQSO”), stock appreciation rights (“SAR”), restricted stock units (“RSU”) or other stock-based award. Instead, ordinary income generally is required to be recognized on the date the NQSO or SAR is exercised or, in the case of RSU awards or other stock-based awards, upon the issuance of shares or receipt of cash pursuant to the terms of the award. In general, the amount of ordinary income required to be recognized is: (i) in the case of a NQSO, an amount equal to the excess, if any, of the aggregate fair market value of the shares of our Common Stock underlying the options exercised over the aggregate exercise price, (ii) in the case of a SAR, the amount of cash or the fair market value of any shares received upon exercise, plus the amount of cash or the fair market value of any shares that were withheld in satisfaction of any applicable taxes due upon the exercise of the award, and (iii) in the case of RSU awards or other stock-based awards, the amount of cash or the fair market value of any shares received in respect thereof, plus the amount of cash or the fair market value of any shares that were withheld in satisfaction of any applicable taxes due on the vesting or payment of such awards.

Incentive Stock Options. A grantee is not taxed at the time an incentive stock option (“ISO”) is granted. The tax consequences upon exercise and later disposition depend upon whether the grantee holds the shares received upon exercise of an ISO for more than one year after exercise and two years after the date of grant of the option. If the grantee satisfies this holding period, for regular tax purposes the grantee will not realize income upon exercise of the ISO, and the Company will not be allowed an income tax deduction at any time with respect to the ISO. The difference between the exercise price and the amount realized upon disposition of the shares by the grantee will constitute a long-term capital gain or a long-term capital loss, as the case may be. If the grantee fails to meet the holding period (other than by reason of death), a disqualifying disposition occurs and the grantee generally recognizes as ordinary income, in the year of the disqualifying disposition, an amount equal to the excess of the fair market value of the shares at the date of exercise over the exercise price. Any excess of the sales price over the fair market value at the date of exercise will be recognized by the grantee as long-term or short-term capital gain, depending on the length of time the shares were held after the option was exercised. If, however, the sales price is less than the fair market value at the date of exercise, then the ordinary income recognized by the grantee is generally limited to the excess (if any) of the sales price over the exercise price. In both situations, the Company’s tax deduction is limited to the amount of ordinary income recognized by the grantee. Different consequences apply for a grantee subject to the alternative minimum tax.

Restricted Shares. A grantee generally is not required to recognize ordinary income on the award of restricted shares of Common Stock. Instead, on the date the shares vest (i.e., become transferable and no longer subject to forfeiture), the grantee will be required to recognize ordinary income in an amount equal to the excess, if any, of the fair market value of the shares on such date over the amount, if any, paid for such shares. Any dividends received upon vesting

of the related restricted shares generally will be treated as compensation that is taxable as ordinary income to the recipient. If permitted by the applicable award agreement, a grantee may make an election under Section 83(b) of the Code to recognize ordinary income on the date the restricted shares are granted in an amount equal to the excess (if any) of the fair market value of the shares over any amount paid for such shares.

Disposition of Shares. Unless stated otherwise above, upon the subsequent disposition of shares of Common Stock acquired under any of the preceding awards, a grantee will recognize capital gain or loss based upon the difference between the amount realized on such disposition and the grantee’s basis in the shares, and such amount will be long-term capital gain or loss if such shares were held for more than 12 months.

Deductibility by the Company. Unless stated otherwise above, to the extent that a grantee recognizes ordinary income in the circumstances described above, the Company generally will be entitled to a corresponding deduction, provided that, among other things, the deduction is not disallowed under Section 162(m) of the Code.

Effect of Change in Control. Under the “golden parachute” provisions of Section 280G of the Code, the accelerated vesting, exercisability or payout of awards under the 2026 Omnibus Plan in connection with a change in control may be required to be valued and taken into account in determining whether grantees have received compensatory payments contingent upon the change in control in excess of certain limits. If these limits are exceeded, a portion of the amounts payable to the grantees may be subject to an additional 20% federal tax and may be nondeductible to the Company.

Section 409A. Certain awards under the 2026 Omnibus Plan may constitute nonqualified deferred compensation under Section 409A of the Code. Failure to satisfy the applicable requirements under Section 409A for awards considered deferred compensation would result in the acceleration of income and additional income tax liability to the recipient, including certain penalties. Awards under the 2026 Omnibus Plan are intended to be designed and administered so that they comply with, or are exempt from, Section 409A to avoid the imposition of additional tax, penalties, and interest on the grantee.

Tax Withholding. Awards under the 2026 Omnibus Plan may be subject to tax withholding. Where an award results in income subject to withholding, the Company may require the grantee to remit the withholding amount to the Company or cause shares of Common Stock to be withheld or sold in order to satisfy the tax withholding obligations. If shares of Common Stock are withheld or sold to satisfy a grantee’s tax withholding obligations, the grantee will be treated as having received such shares for purposes of the discussion above.

New Plan Benefits

Because grants under the 2026 Omnibus Plan are discretionary, the Company cannot now determine the number of awards that will be granted in the future to any particular executive officer, to all executive officers as a group or to non-executive officer employees or directors as a group. The number of such awards will be determined by the Compensation Committee from time to time in accordance with the terms of the 2026 Omnibus Plan.

Market Value

As of April 8, 2026, the closing price of the Company’s common stock was $33.09.

Registration with the SEC

If our stockholders approve the 2026 Omnibus Plan, the Company intends to file with the SEC a Registration Statement on Form S-8, as soon as reasonably practicable after the approval, to register the new shares available for issuance under the 2026 Omnibus Plan.

Required Vote

The approval of the 2026 Omnibus Plan requires the affirmative vote of the holders of a majority of the shares present in person (virtually) or represented by proxy at the Annual Meeting and entitled to vote on the proposal. Abstentions

will have the same effect as a vote against the proposal. Broker non-votes will not be counted as shares entitled to vote on the proposal.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR” THE APPROVAL OF THE BYLINE BANCORP, INC. 2026 OMNIBUS INCENTIVE COMPENSATION PLAN.

Description of Amendment

At the Annual Meeting, stockholders will be requested to approve an increase by 200,000 in the number of shares available for issuance under the ESPP. At current participation levels and the Company’s current stock price, we estimate that, in the absence of approval of increase in the number of shares of common stock that may be offered under the ESPP, all such shares could be substantially exhausted before the end of 2026. If the amendment is approved by stockholders, the number of shares available under the ESPP will be increased to 231,343. We believe that this increase in the number of shares available under the ESPP will enable eligible persons to participate under the ESPP until approximately December 31, 2029, based on current participation levels and the current price of our common stock.

Summary of the ESPP

The following is a description of the material terms of the ESPP, as proposed to be amended. This description is qualified in its entirely by reference to the plan document, as proposed to be amended, a copy of which is attached to this Proxy Statement as Annex 2 and incorporated herein by reference.

Administration

The ESPP is administered by the Compensation Committee of our Board of Directors, who may delegate its administrative authority to a person or committee who shall serve as the “Plan Administrator.” The Compensation Committee has delegated such authority to our Chief Human Resources Officer. The Plan Administrator has the authority to make and adopt rules and regulations not inconsistent with the provisions of the ESPP or the Internal Revenue Code of 1986, as amended (the “Code”). In addition, the Plan Administrator corrects any defect or supplies any omission or reconciles any inconsistency in the ESPP. The interpretations and decisions of the Plan Administrator in respect to the ESPP will be final and binding.

Eligible Employees

All of our employees or employees of participating subsidiaries, as defined in the ESPP, whose customary term of employment is for more than 20 hours per week, are eligible to participate in the ESPP. In addition, no employee may purchase shares of our common stock under the ESPP that would result in the employee owning 5% or more of the total combined voting power or value of our stock or the stock of any of our subsidiaries.

Offerings

From time to time, the Company offers employees the opportunity to buy stock in the Company through the ESPP. Unless determined otherwise by the Compensation Committee, offerings begin on January 1 and July 1 of each year and last for a period of six months. The Compensation Committee will establish an enrollment period, a period of time prior to the beginning of an offering during which eligible participants may subscribe to an offering in such manner as the Compensation Committee may prescribe (which may include enrollment by submitting forms, by voice response, internet access or other electronic means). Eligible employees elect whether to participate in the ESPP (i.e., have deductions made from their after-tax compensation for the purpose of buying shares) during the enrollment period.

Each eligible employee who is a participant as of the date an offering commences is deemed to be granted an option to participate in the ESPP for that offering. The Compensation Committee may also establish a waiting period of up to two years after an employee is first employed before the employee may participate or permit employees who are hired during an offering period to participate in the offering. On the last day of each offering period, the accumulated balance in each participant’s account will be used to purchase shares at the purchase price described below. The Compensation Committee may also provide for periodic purchase dates during an offering period.

A participant can change his or her level of withholding or withdraw his or her subscription at any time (but not retroactively), during an offering, subject to rules and limitations established by the Plan Administrator. A participant whose employment is terminated during an offering period is deemed to have withdrawn his or her subscription. Upon the withdrawal (or deemed withdrawal) of a participant, the balance in his or her account will either be refunded or used to purchase shares on the next purchased date, as determined by the Compensation Committee.

Purchase Price

The purchase price paid by participants for the shares purchased under the ESPP is set by the Compensation Committee and will, in any case, be no less than 85% of the lower of the fair market value of a share of our common stock on the first day of the applicable offering period or on the purchase date. Unless provided otherwise, the default purchase price per share provided for in the ESPP will be 85% of the fair market value of a share of our common stock on the last day of the applicable offering period or earlier purchase date.

Limitations on Purchase

As required by the Code, no eligible employee may purchase stock under the ESPP at a rate which, when aggregated with his or her other rights to purchase our common stock, exceeds $25,000 in fair market value per year. Unless the Plan Administrator determines otherwise, employees are also limited in making elections under the ESPP to contributing no more than 15% of their after-tax compensation to the ESPP.

Mandatory Retention or Sale of Stock

To facilitate compliance with applicable law, the Compensation Committee may require participants to (a) retain any shares purchased under the ESPP for a designated period of time or may establish other

procedures to restrict transfer of such shares or (b) sell shares immediately upon purchase or within a specified period following a termination of employment.

Adjustments

In the event of a stock split, stock dividend, reverse stock split, extraordinary cash dividend, recapitalization, reorganization, reclassification or combination of shares, merger, consolidation, distribution, split-up, spin-off, exchange of shares, sale of assets or similar corporate transaction or event, the Compensation Committee, in the manner it deems equitable, will adjust (a) the number and class of shares or other securities reserved for issuance under the ESPP, (b) the number and class of shares or other securities that are subject to outstanding options, and (c) the appropriate market value and other price determinations applicable to options (including the purchase price).

Termination and Amendment of the ESPP

Our Compensation Committee generally may, at any time, terminate or amend the ESPP in any respect, except that, without approval of our stockholders, no amendment may increase the maximum number of our shares reserved under the ESPP or modify the requirements as to eligibility for participation in the ESPP. No termination or amendment of the ESPP may terminate or materially and adversely affect a participant’s rights under the ESPP without such participant’s consent. Unless earlier terminated by the Compensation Committee, the ESPP will terminate when no remaining shares are available for issuance under the ESPP.

Required Vote

The approval of the amendment to the ESPP requires the affirmative vote of the holders of a majority of the shares present in person (virtually) or represented by proxy at the Annual Meeting and entitled to vote on the proposal. Abstentions will have the same effect as a vote against the proposal. Broker non-votes will not be counted as shares entitled to vote on the proposal.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR” THE AMENDMENT TO THE COMPANY’S EMPLOYEE STOCK PURCHASE PLAN TO INCREASE THE NUMBER OF SHARES OF COMMON STOCK THAT MAY BE OFFERED UNDER THE PLAN

The Board is submitting for ratification by our stockholders at the Annual Meeting the appointment of Baker Tilly as our independent registered public accounting firm for the fiscal year ending December 31, 2026. In considering the reappointment of Baker Tilly for 2026, the Audit Committee reviewed, among other considerations, the quality of services provided, both historically and in connection with the most recent audit; Baker Tilly’s capability and expertise, particularly with respect to the financial services industry and its resources; the communication and interaction by Baker Tilly’s audit team with the Audit Committee and management; the firm’s independence, objectivity and professional skepticism; and the appropriateness of Baker Tilly’s fees.

The Board has invited representatives of Baker Tilly to be present at the Annual Meeting and expects that they will attend. If present, these representatives will have the opportunity to make a statement if they desire to do so and are expected to be available to respond to appropriate questions from stockholders.

Fees Paid to Baker Tilly US, LLP

The following is a summary and description of the aggregate fees for professional services provided by Moss Adams LLP and Baker Tilly US, LLP to the Company and its subsidiaries for the fiscal years ended December 31, 2025, and 2024, as well as all out-of-pocket costs incurred in connection with these services that were billed to us.

Audit Fees. Audit fees consist primarily of fees and expenses for the audits of our annual consolidated financial statements as well as the review of interim condensed consolidated financial information included in the reports we filed with the SEC. Also included are fees for services normally provided by an independent auditor in connection with statutory and regulatory filings. Audit fees for 2025 include fees incurred by the Company in connection with consent and comfort letter processes and procedures related to the filings with the SEC of registration statements on Form S-3 and Form S-4.

Audit-Related Fees. Audit-related fees consist of fees related to the audit of the financial statements of our 401(k) Plan.

Audit Committee Preapproval Policies and Procedures

All of the fees and services described above under “audit fees” and “audit-related fees” were pre-approved by the Audit Committee. Pursuant to its charter, the Audit Committee pre-approves all audit and permissible non-audit services provided by the independent public accounting firm. These services may include audit services, audit-related services, tax services and other services. In connection with the pre-approval of any permissible tax services or services related to internal control over financial reporting, the Audit Committee charter provides that

the Audit Committee will discuss with the independent public accounting firm the potential impact on the firm’s independence in providing such services. Any pre-approval is subject to receipt of details as to the service or category of services to be provided and the provision of supporting documentation at the time of approval. The Audit Committee may delegate pre-approval authority to one or more of its members. Such member(s) must report any decisions to the Audit Committee at the next scheduled meeting.

Required Vote

The ratification of the appointment of Baker Tilly US, LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2026, requires the affirmative vote of the holders of a majority of the shares present in person (virtually) or represented by proxy at the Annual Meeting and entitled to vote on the proposal. Abstentions will have the same effect as a vote against the proposal. Broker non-votes will not be counted as shares entitled to vote on the proposal.

THE BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE “FOR” THE RATIFICATION OF THE APPOINTMENT OF BAKER TILLY US, LLP AS THE COMPANY’S INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR THE 2026 FISCAL YEAR.

Report of the Audit Committee

The Audit Committee of the Board of Directors is responsible for providing independent, objective oversight of the Company’s accounting functions and internal controls and is composed of directors that are “independent” as defined under the NYSE corporate governance listing standards and Rule 10A-3 of the Exchange Act. The Audit Committee operates under a written charter approved by the Board of Directors and held 14 meetings during fiscal year 2025. A copy of the charter is available on our website at www.bylinebancorp.com under the “Corporate Governance Documents” tab.

Management is responsible for the Company’s internal control over financial reporting, disclosure controls and procedures and the financial reporting process. The independent registered public accounting firm is responsible for performing an independent audit of our consolidated financial statements in accordance with Public Company Accounting Oversight Board (PCAOB) standards and to issue reports thereon. The Audit Committee’s responsibility is to monitor and oversee these processes, including the activities of the Company’s internal audit function. The Audit Committee has established a mechanism to receive, retain and process complaints on auditing, accounting and internal control issues, including the confidential, anonymous submission by employees and others of concerns on questionable accounting and auditing matters.

In connection with these responsibilities, the Audit Committee met with management and the independent registered public accounting firm to review and discuss the 2025 audited consolidated financial statements. The Audit Committee also discussed with the independent registered public accounting firm the matters required by the applicable requirements of the PCAOB and the SEC. In addition, the Audit Committee received the written disclosures and letter from the independent registered public accounting firm required by applicable requirements of the PCAOB regarding the independent accountant’s communications with the Audit Committee concerning independence, and the Audit Committee has discussed with the independent registered public accounting firm its independence from the Company and its management.

Based upon the Audit Committee’s discussions with management and the independent registered public accounting firm, and the Audit Committee’s review of the representations of management and the independent registered public accounting firm, the Audit Committee recommended that the Board of Directors include Byline’s 2025 audited consolidated financial statements in our Annual Report on Form 10-K for fiscal 2025 filed with the SEC.

This report is submitted on behalf of the current members of the Audit Committee:

This report shall not be deemed to be incorporated by reference by any general statement incorporating by reference this Proxy Statement into any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, and shall not otherwise be deemed filed under such acts.

Executive Compensation

Compensation Discussion and Analysis

This Compensation Discussion & Analysis (“CD&A”) explains our executive compensation program for our named executive officers (“NEOs”) listed below. This CD&A also describes the Compensation Committee’s process for making pay decisions, as well as its rationale for specific decisions related to the fiscal year ended December 31, 2025.

EXECUTIVE SUMMARY

2025 Performance Highlights

Byline advanced its strategy of becoming the preeminent commercial bank in Chicago and delivered strong financial results for 2025. We made significant progress across our strategic priorities deepening our commercial presence, growing customers, and executing initiatives that strengthened our franchise. We remain focused on consistent execution of our strategy, supporting our customers, and driving long-term value for our stockholders. We delivered solid full year 2025 results reflecting record revenues of $446.4 million.

Key financial and strategic highlights for 2025 included:

We continue to take a prudent and disciplined approach to expense management to drive full-year positive operating leverage, while investing in the future. We are balancing continuous improvements and investments for growth, in addition to balancing physical branch presence with our digital offerings.

Good Compensation Governance

The program is built on a foundation of best-in-class compensation governance practices and policies:

As we continue to grow profitably and strategically, the Compensation Committee will review and adjust the design of the executive compensation program to ensure it remains aligned with our business objectives, talent strategy and market practices.

2025 Executive Compensation Program At-A-Glance

The objective of our executive compensation program is to attract, retain, and motivate leaders who are committed to executing on our business strategy and creating long-term value for our stakeholders. To help us achieve these objectives, the Compensation Committee has designed an executive compensation program that consists of fixed and variable pay elements in the form of base salaries, annual short-term cash and long-term equity incentives. Our executive compensation program emphasizes performance-based compensation and is designed to tie directly to the drivers of value creation for the Company’s stockholders, as generally summarized below.

Consistent with the design of our program summarized above, the Compensation Committee made the following executive compensation decisions for fiscal year 2025:

As the Company continues to grow profitably and strategically, the Compensation Committee will review and adjust the design of the executive compensation program to ensure it remains aligned with our business objectives, talent strategy and market practices.

WHAT GUIDES OUR PROGRAM

Executive Compensation Philosophy & Objectives

To accomplish our business and growth objectives, we must be able to attract and retain talented executives whose skills and experience enable them to contribute to our long-term success. To that end, the philosophy and principal objectives of our executive compensation programs are to attract, fairly compensate, appropriately incentivize, and retain superior executive talent in a manner that aligns their long-term interests with those of our stockholders. Our compensation philosophy, policy and program supports, reinforces, and aligns our values, business strategy, operational, and financial needs with the goals of profitability and growth, while operating in a safe and prudent manner.

We operate a compensation philosophy based on key principles that guide the development of our compensation programs, practices, and policies. These key principles include, but are not limited to, the following:

Our executive compensation program is designed to be:

The Decision-Making Process

The Role of the Compensation Committee. The Compensation Committee sets and administers the policies that govern our executive compensation programs and is responsible for discharging the Board’s responsibilities relating to compensation of our executive officers and directors. The Compensation Committee has adopted a written charter that, among other things, specifies the scope of its rights and responsibilities. A copy of the Committee’s charter is available on our website at www.bylinebancorp.com under the “Corporate Governance Documents” tab. The Compensation Committee is composed solely of members who satisfy the applicable independence requirements of the NYSE as they apply to members of compensation committees.

The Role of Management. Our Chief Executive Officer, President, and Chief Human Resources Officer, working with internal resources as well as with our Compensation Committee’s compensation consultant, review our

executive compensation program on an annual basis and make recommendations as to the type and amount of compensation based on the review of peer group and other market data, individual performance and other factors. Our Chief Executive Officer and President make recommendations to our Compensation Committee regarding the compensation of our executives other than themselves based on these same factors. The Chief Executive Officer and President do not participate in or make recommendations with respect to their own compensation and are not present during such discussions or determinations. The Compensation Committee oversees the Board’s review of the performance of the Chief Executive Officer and receives input from the Chief Executive Officer on the President’s performance and recommended compensation. As with the reviews of all other NEOs, these reviews are based on the individual’s performance and contribution toward our performance during the year. Based on the review, the Compensation Committee determines, in its sole discretion, whether to make adjustments to the base salary, annual cash incentive, equity award amounts or other compensation for the Chief Executive Officer and President.

The Role of the Independent Compensation Consultant. In 2025, the Compensation Committee retained Pearl Meyer primarily to assist the Compensation Committee in determining and structuring executive compensation and to assess the market competitiveness of the Company’s executive compensation program. The Compensation Committee has annually engaged Pearl Meyer for these and related services since 2014. With respect to any advice provided to the Committee by Pearl Meyer, the Compensation Committee received a letter from Pearl Meyer addressing factors relevant to SEC and NYSE rules regarding independence and conflicts of interest. After considering the information provided by Pearl Meyer and other factors, no conflicts of interest with respect to Pearl Meyer were identified by the Compensation Committee, and the Compensation Committee concluded that Pearl Meyer was an independent consultant.

Compensation Benchmarking and Decisions

The Compensation Committee’s objective is to set a competitive level of total compensation for each NEO as compared with executive officers in similar positions at peer companies. For purposes of benchmarking 2025 compensation levels, in conjunction with the recommendation of Pearl Meyer, the Compensation Committee considered publicly available data for a group of peer companies listed below along with industry-specific survey data where appropriate. Selection criteria used to establish the competitive market for the NEOs, generally include:

Based on the analysis, a peer group of 23 companies used in benchmarking the 2025 executive compensation included the following:

Executive Compensation Program in Detail

Elements of Pay: Total Direct Compensation