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 January 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 S      Form 40-F £

EXHIBIT INDEX

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: January 28, 2026