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 April, 2025

Commission File Number 001-34175

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 ¨

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 x

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 x

Indicate by check mark whether the registrant by furnishing the information contained in this form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes ¨      No x

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82- N/A

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: April 22, 2025

Ecopetrol Publishes Periodic Year-End Report for 2024

Ecopetrol S.A. (BVC: ECOPETROL; NYSE: EC) has published the periodic year-end report for 2024, which contains sections related to company practices, policies, processes and indicators in connection with social and environmental matters, including climate issues. This report was published pursuant to External Circulars 012 of 2022 and 031 of 2021, both issued by the Financial Superintendence of Colombia (Superintendencia Financiera de Colombia).

Ecopetrol has also published the legal representative letter certifying that the financial statements and other relevant reports to the public do not contain inaccuracies or errors that prevent the true financial situation or operations of Ecopetrol S.A. from being known.

The report and the legal representative letter can be consulted in Spanish in the following link:

https://www.ecopetrol.com.co/wps/portal/Home/es/Inversionistas/InformacionFinanciera/Informacionrelevante

Bogota D.C., April 22, 2025

Ecopetrol is the largest company in Colombia and one of the mainintegrated energy companies in the American continent, with more than 19,000 employees. In Colombia, it is responsible for more than 60%of the hydrocarbon production of most transportation, logistics, and hydrocarbon refining systems, and it holds leading positions in thepetrochemicals and gas distribution segments. With the acquisition of 51.4% of ISA’s shares, the company participates in energytransmission, the management of real-time systems (XM), and the Barranquilla - Cartagena coastal highway concession. At the internationallevel, Ecopetrol has a stake in strategic basins in the American continent, with Drilling and Exploration operations in the United States(Permian basin and the Gulf of Mexico), Brazil, and Mexico, and, through ISA and its subsidiaries, Ecopetrol holds leading positions inthe power transmission business in Brazil, Chile, Peru, and Bolivia, road concessions in Chile, and the telecommunications sector.

This release contains statements that may be considered forward-lookingstatements within the meaning of Section 27A of the U.S. Securities Act of 1933, as amended, and Section 21E of the U.S. Securities ExchangeAct of 1934, as amended. All forward-looking statements, whether made in this release or in future filings or press releases, or orally,address matters that involve risks and uncertainties, including in respect of the Company’s prospects for growth and its ongoingaccess to capital to fund the Company’s business plan, among others. Consequently, changes in the following factors, among others,could cause actual results to differ materially from those included in the forward-looking statements: market prices of oil & gas,our exploration, and production activities, market conditions, applicable regulations, the exchange rate, the Company’s competitivenessand the performance of Colombia’s economy and industry, to mention a few. We do not intend and do not assume any obligation to updatethese forward-looking statements.

For more information, please contact:

Head of Capital Markets

Carolina Tovar Aragón

Email: investors@ecopetrol.com.co

Head of Corporate Communications (Colombia)

Marcela Ulloa

Email: marcela.ulloa@ecopetrol.com.co