President and Chief Financial Officer — Celso L. Goncalves Jr.: Celso Goncalves was promoted to President and retained as Chief Financial Officer, with Lourenco Goncalves continuing as Chairman and CEO.

Results of Operations and Financial Condition. On July 23, 2026, Cleveland-Cliffs Inc. issued a news release announcing the second-quarter financial results for the quarter ended June 30, 2026. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Current Report on Form 8-K, including the exhibit attached hereto, is being furnished and shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchang…

Results of Operations and Financial Condition. On April 20, 2026, Cleveland-Cliffs Inc. issued a news release announcing the first-quarter financial results for the quarter ended March 31, 2026. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Current Report on Form 8-K, including the exhibit attached hereto, is being furnished and shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchan…

Lead Director of the Board — Douglas C. Taylor: Mr. Taylor resigned due to a change in his primary occupation, position or primary business affiliation.

Results of Operations and Financial Condition. On February 9, 2026, Cleveland-Cliffs Inc. issued a news release announcing the fourth-quarter and full-year financial results for the period ended December 31, 2025. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Current Report on Form 8-K, including the exhibit attached hereto, is being furnished and shall not be deemed to be filed for the purposes of Section 18 of th…

Director — Edilson Camara: The filing discloses the appointment of a new independent director to the board, which is a routine governance event and not a departure of a senior executive.

Results of Operations and Financial Condition. On October 20, 2025, Cleveland-Cliffs Inc. issued a news release announcing the third-quarter financial results for the quarter ended September 30, 2025. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Current Report on Form 8-K, including the exhibit attached hereto, is being furnished and shall not be deemed to be filed for the purposes of Section 18 of the Securities…

by reference. 3 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 hereunto duly authorized. CLEVELAND-CLIFFS INC. Date: October 10, 2025 By: /s/ James D. Graham Name: James D. Graham Title: Executive Vice President, Chief Legal and Administrative Officer & Secretary 4

Entry into a Material Definitive Agreement. On October 10, 2025, Cleveland-Cliffs Inc. (the “Company”) issued an additional $275,000,000 aggregate principal amount of 7.625% Senior Guaranteed Notes due 2034 (the “Additional Notes”) in a private transaction exempt from the registration requirements of the Securities Act of 1933 (the “Securities Act”). The Additional Notes have not been, and will not be, registered under the Securities Act and may not be offered or sold in the United States abs…

Other Events. On October 7, 2025, Cleveland-Cliffs Inc. (the “Company”) announced that it launched and priced a private offering of an additional $275 million aggregate principal amount of 7.625% Senior Guaranteed Notes due 2034 (the “Additional Notes”) in an offering exempt from the registration requirements of the Securities Act of 1933 (the “Securities Act”). The Additional Notes will be an issuance of the Company’s existing 7.625% Senior Guaranteed Notes due 2034 and will be issued as add…

Entry into a Material Definitive Agreement. On September 8, 2025, Cleveland-Cliffs Inc. (the “Company”) issued $850,000,000 aggregate principal amount of 7.625% Senior Guaranteed Notes due 2034 (the “Notes”) in a private transaction exempt from the registration requirements of the Securities Act of 1933 (the “Securities Act”). The Notes have not been, and will not be, registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable e…

by reference. 3 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 hereunto duly authorized. CLEVELAND-CLIFFS INC. Date: September 8, 2025 By: /s/ James D. Graham Name: James D. Graham Title: Executive Vice President, Chief Legal and Administrative Officer & Secretary 4

Other Events. Notes Offering On September 3, 2025, Cleveland-Cliffs Inc. (the “Company”) announced that it launched and priced a private offering of $850 million aggregate principal amount of Senior Guaranteed Notes due 2034 (the “Notes”) in an offering exempt from the registration requirements of the Securities Act of 1933 (the “Securities Act”). The Notes will bear interest at an annual rate of 7.625% and will be issued at par. The Notes offering is expected to close on September 8, 2025, s…

Results of Operations and Financial Condition. On July 21, 2025, Cleveland-Cliffs Inc. issued a news release announcing the second-quarter financial results for the quarter ended June 30, 2025. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Current Report on Form 8-K, including the exhibit attached hereto, is being furnished and shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchang…

Results of Operations and Financial Condition. On May 7, 2025, Cleveland-Cliffs Inc. issued a news release announcing the first-quarter financial results for the quarter ended March 31, 2025. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Current Report on Form 8-K, including the exhibit attached hereto, is being furnished and shall not be deemed to be filed for the purposes of Section 18 of the Securities Exchange…

Results of Operations and Financial Condition. On February 24, 2025, Cleveland-Cliffs Inc. issued a news release announcing the fourth-quarter and full-year financial results for the period ended December 31, 2024. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Current Report on Form 8-K, including the exhibit attached hereto, is being furnished and shall not be deemed to be filed for the purposes of Section 18 of t…

Entry into a Material Definitive Agreement. On February 6, 2025, Cleveland-Cliffs Inc. (the “Company”) issued $850,000,000 aggregate principal amount of 7.500% Senior Guaranteed Notes due 2031 (the “Notes”) in a private transaction exempt from the registration requirements of the Securities Act of 1933 (the “Securities Act”). The Notes have not been, and will not be, registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable ex…

by reference. 3 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 hereunto duly authorized. CLEVELAND-CLIFFS INC. Date: February 6, 2025 By: /s/ James D. Graham Name: James D. Graham Title: Executive Vice President, Chief Legal and Administrative Officer & Secretary 4

Results of Operations and Financial Condition. On February 3, 2025, Cleveland-Cliffs Inc. (the “Company”) issued a press release announcing preliminary fourth-quarter and full-year 2024 financial results for the period ended December 31, 2024. A copy of the press release is attached hereto as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference. The information contained in this

Other Events. On February 3, 2025, the Company announced that it launched and priced a private offering of $850 million aggregate principal amount of Senior Guaranteed Notes due 2031 (the “Notes”) in an offering exempt from the registration requirements of the Securities Act. The Notes will bear interest at an annual rate of 7.500% and will be issued at par. The Notes offering is expected to close on February 6, 2025, subject to the satisfaction of customary closing conditions. A copy of the…

Director — Jane M. Cronin: The filing discloses the appointment of a new independent director to the Board and Audit Committee, which is a routine governance event rather than a departure of a senior executive.

Results of Operations and Financial Condition. On November 4, 2024, Cleveland-Cliffs Inc. issued a news release announcing the third-quarter financial results for the quarter ended September 30, 2024. A copy of the news release is attached as Exhibit 99.1 to this Current Report on Form 8-K. The information contained in this Current Report on Form 8-K, including the exhibit attached hereto, is being furnished and shall not be deemed to be filed for the purposes of Section 18 of the Securities…

Completion of Acquisition or Disposition of Assets. The information set forth in the Introductory Note of this Current Report on Form 8-K is incorporated herein by reference.

Entry into a Material Definitive Agreement. On October 22, 2024, Cleveland-Cliffs Inc. (the “Company”) issued $900,000,000 aggregate principal amount of 6.875% Senior Guaranteed Notes due 2029 (the “2029 Notes”) and $900,000,000 aggregate principal amount of 7.375% Senior Guaranteed Notes due 2033 (the “2033 Notes” and, together with the 2029 Notes, the “Notes”) in a private transaction exempt from the registration requirements of the Securities Act of 1933 (the “Securities Act”). The Notes h…

by reference. 3 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 hereunto duly authorized. CLEVELAND-CLIFFS INC. Date: October 22, 2024 By: /s/ James D. Graham Name: James D. Graham Title: Executive Vice President, Chief Legal and Administrative Officer & Secretary 4