Transocean Ltd.

Item 7.01 Regulation FD Disclosure. ​ Transocean Ltd. (NYSE: RIG) ("Transocean") today announced that the Deepwater Corcovado was awarded a 1,156-day contract extension with Petrobras in direct continuation of its current activity. The extension is expected to contribute approximately $445 million in incremental backlog and commit the rig through November 2030. Prior to the extension period, from April 1, 2026, until the commencement of the new contract in September 2027 (approximately 525 days), the existing backlog will be reduced by approximately $20 million. ​ A copy of the press release announcing the fixtures referred to above is attached hereto and incorporated herein by reference as Exhibit 99.1 . ​ Item 9.01 Financial Statements and Exhibits. ​ (d) Exhibits. ​ ​

Exhibit No . ​ ​ ​ Description ​ ​ ​ 99.1 ​ Transocean Ltd. Announces $425 Million Additional Backlog for Ultra-Deepwater Drillship 101 ​ Interactive data files pursuant to Rule 405 of Regulation S-T formatted in Inline Extensible Business Reporting Language 104 ​ Cover Page Interactive Data File (formatted as inline XBRL).