6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

FORM 6-K

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

For the month of June, 2026

Commission File Number: 001-38049

Azul S.A. (Name of Registrant)

Edifício Jatobá, 8th Floor, Castelo Branco Office Park Avenida Marcos Penteado de Ulhôa Rodrigues, 939, Tamboré, Barueri, São Paulo, SP, 06460-040, Brazil

• 55 (11) 4831 2880 (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 ☒    Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Yes ☐    No ☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Yes ☐    No ☒

Enclosures:

Exhibit 99.1 -azul-materialfactxissuance.htmIssuance of Subscription Warrants – Series 4

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.

Date: June 30th, 2026

Document

	Material Fact<br><br>June	2026

Issuance of Subscription Warrants – Series 4

São Paulo, June 30, 2026 – Azul S.A. (B3: AZUL3; NYSE American: AZUL) (“Azul” or “Company”), in compliance with the provisions of the Resolution of the Brazilian Securities and Exchange Commission No. 44, of August 23, 2021, of article 157, paragraph 4, of Law No. 6,404, of December 15, 1976 (“Brazilian Corporations Law ”), and in furtherance to the material fact disclosed on May 21, 2026, the Company informs its shareholders and the market in general that, on the date hereof, the Company’s Board of Directors ratified the final number of warrants to subscribe for common shares of the Company (“Subscription Warrants – Series 4”), the issuance of which was previously approved by the Company’s Board of Directors on May 21, 2026 (“Issuance Board Approval”).

As approved by the Company’s Board of Directors, after verifying the result of the exercise of preemptive rights by the Company’s eligible shareholders, pursuant to article 171, paragraph 3, of the Brazilian Corporations Law and also taking into account the limitations and rules set forth in the Issuance Board Approval, 6,904,589 Subscription Warrants – Series 4 will be issued.

As a result, the Subscription Warrants – Series 4 (B3: AZUL19) will begin to be traded as of July 2, 2026. Pursuant to the Issuance Board Approval, the Subscription Warrants – Series 4 may be exercised until June 30, 2027.

About Azul

Azul S.A. (B3: AZUL3; NYSE American: AZUL), the largest airline in Brazil by departures and cities served, offers approximately 800 daily flights to over 137 destinations. With an operating fleet of over 180 aircraft and more than 14,000 Crewmembers, the Company has a network of 250 non-stop routes. In 2020, Azul was awarded best airline in the world by TripAdvisor, first time a Brazilian Flag Carrier earns number one ranking in the Traveler’s Choice Awards. For more information, visit https://ri.voeazul.com.br.

Contact

Investor Relations                     Press Relations

Tel: +55 11 4831 2880                  Tel: +55 11 98196-1035

[email protected] [email protected]

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