FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * Rosenberg Whitaker Carneiro Ralph Gustavo	2. Date of Event Requiring Statement (MM/DD/YYYY) 3/18/2026	3. Issuer Name and Ticker or Trading Symbol Cosan S.A. [CSAN] 3a. Foreign Trading Symbol [CSAN3]
(Last)        (First)        (Middle) RUA LEOPOLDO COUTO MAGALHAES JUNIOR 822, 1ST FLOOR	4. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director                          _____ 10% Owner _____ Officer (give title below)        _____ Other (specify below)
(Street) SAO PAULO SP 04542-000       (City)              (State)              (Zip/Postal Code)	5. If Amendment, Date Original Filed(MM/DD/YYYY)	6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person
BRAZIL
(Country)

Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
COMMON STOCK (CSAN3) (1)	4,251,582	I	CLASSE A DO PERFIN RALLY FUNDO DE INVESTIMENTO EM PARTICIPACOES MULTIESTRATEGIA RESP LIMITADA

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:
(1)	Mr. Carneiro owns common stock of Cosan S.A. through the investment fund, Classe A do Perfin Rally Fundo de Investimento em Participacoes Multiestrategia Responsabilidade Limitada. Mr. Carneiro disclaims beneficial ownership of the shares held by the investment fund except to the extent, if any, of his pecuniary interest therein.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Rosenberg Whitaker Carneiro Ralph Gustavo RUA LEOPOLDO COUTO MAGALHAES JUNIOR 822, 1ST FLOOR SAO PAULO SP 04542-000 BRAZIL	X

Signatures
/s/ Ralph Gustavo Rosenberg Whitaker Carneiro		3/18/2026
**Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.
* Form 3: SEC 1473 (03-26).