6-K

UNITEDSTATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDERTHE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2026

Commission File Number: 001-32702

Almaden Minerals Ltd. (Translation of registrant's name into English)

Suite 210 - 1333 Johnston Street, Vancouver V6H 3R9 (Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F. Form 20-F [ X ]      Form 40-F [   ]

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

EXHIBITINDEX

Exhibit 99.1

FORM 51-102F3

MATERIAL CHANGE REPORT

Almaden Minerals Ltd. (“Almaden” or the “Company”)

210 - 1333 Johnson Street

Vancouver, British Columbia

V6H 3R9

May 19, 2026

A news release was issued and disseminated via GLOBE NEWSWIRE by the Company on May 21, 2026.

Almaden has continued with its international arbitration proceedings (the “Claim”) against the United Mexican States (“Mexico”) under the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (“CPTPP”), by filing its Reply submission (“Reply”) with the International Centre for Settlement of Investment Disputes (“ICSID”).

Almaden is pursuing this Claim together with Almadex Minerals Ltd. (“Almadex”), on behalf of themselves and their Mexican subsidiaries (the “Claimants”). Prior to the illegal acts of Mexico which resulted in the complete loss of the investment, Almaden held 100% of the Ixtaca precious metals project in Mexico (the “Project”), while Almadex held a 2.0% NSR royalty on the Project.

The Reply builds upon and adds to the independent expert reports and witness statements that formed part of the Memorial, and the Claimants are now seeking damages of US$2.68 billion, in the aggregate. This number may be further updated as the Claim proceeds, to reflect future movements in precious metal prices, exchange rates, interest rates, and other factors.

Almaden announced that it had filed its Reply relating to the Claim against Mexico with ICSID.

The Claim is being prosecuted pursuant to the established and enforceable legal framework of ICSID and is being funded through a US$9.5 million non-recourse litigation funding agreement provided by a leading legal finance counterparty (see June 27, 2024 press release).

As further explained in the Company’s June 27, 2024 press release, Almaden is pursuing this Claim together with Almadex, on behalf of themselves and their Mexican subsidiaries. Prior to the illegal acts of Mexico which resulted in the complete loss of the investment, Almaden held 100% of the Ixtaca precious metals Project in Mexico, while Almadex held a 2.0% NSR royalty on the Project.

The Reply comprehensively addresses the arguments presented in Mexico’s Counter Memorial of December, 2025 and outlines Mexico’s breaches of the CPTPP through:

The Reply builds upon and adds to the independent expert reports and witness statements that formed part of the Memorial. Among the reports filed as part of the Reply is an independent quantum expert report, updated to reflect movements in precious metal prices, interest rates, and other factors since the Claimant’s Memorial filing in March, 2025. Based on this updated quantum estimate the Claimants now seek damages in the amount of US$2.68 billion, in the aggregate. This number may be further updated as the Claim proceeds, to reflect future movements in precious metal prices, exchange rates, interest rates, and other factors.

The next steps in the arbitration process include Mexico filing its Rejoinder to the Claimants’ Reply, which is currently scheduled for late August, 2026 and then the in-person hearing in Washington D.C, currently scheduled for December 14-18, 2026.

Not applicable.

Not applicable.

There are no significant facts required to be disclosed herein which have been omitted.

For further information, please contact:

Douglas McDonald, President & CEO

(604) 689-7644

[email protected]

May 28, 2026

Safe Harbor Statement

Certain of the statements and information in this materialchange report constitute “forward-looking statements” within the meaning of the United States Private Securities LitigationReform Act of 1995 and “forward-looking information” within the meaning of applicable Canadian provincial securities laws.All statements, other than statements of historical fact, are forward-looking statements or information. Forward-looking statements orinformation in this material change report relate to, among other things, the timing of any update regarding the arbitration calendar.

These forward-looking statements and information reflectthe Company’s current views with respect to future events and are necessarily based upon a number of assumptions that, while consideredreasonable by the Company, are inherently subject to significant legal, regulatory, business, operational and economic uncertainties andcontingencies, and such uncertainty generally increases with longer-term forecasts and outlook. These assumptions include: stability andpredictability in Mexico’s response to the arbitration process under the CPTPP; stability and predictability in the applicationof the CPTPP and arbitral decisions thereon; the ability to continue to finance the arbitration process, and continued respect for therule of law in Mexico. The foregoing list of assumptions is not exhaustive.

The Company cautions the reader that forward-looking statementsand information involve known and unknown risks, uncertainties and other factors that may cause actual results and developments to differmaterially from those expressed or implied by such forward-looking statements or information contained in this material change report.Such risks and other factors include, among others, risks related to: the application of the CPTPP and arbitral decisions thereon; continuedrespect for the rule of law in Mexico; political risk in Mexico; crime and violence in Mexico; corruption in Mexico; uncertainty as tothe outcome of arbitration or the funding available to the Company to pursue it; as well as those factors discussed the section entitled"Risk Factors" in Almaden's Annual Information Form and Almaden's latest Form 20-F on file with the United States Securitiesand Exchange Commission in Washington, D.C. Although the Company has attempted to identify important factors that could affect the Companyand may cause actual actions, events or results to differ materially from those described in forward-looking statements or information,there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. There can be no assurancethat our forward-looking statements or information will prove to be accurate. Accordingly, readers should not place undue reliance onforward-looking statements or information. Except as required by law, the Company does not assume any obligation to release publicly anyrevisions to on forward-looking statements or information contained in this material change report to reflect events or circumstancesafter the date hereof or to reflect the occurrence of unanticipated events.