Sean O'Malley has three losses against two opponents on his MMA record. For a list of O'Malley's best fights, refer to "Best fights of Sean O'Malley".
On June 7, 2025 Sean O'Malley fought Merab Dvalishvili in a bantamweight title fight for Dvalishvili's UFC Championship title. O'Malley was 30 years old and with a record of 18-3 (13), and Dvalishvili was 34 years old and with a record of 19-4 (4). O'Malley lost the fight via 3rd-round submission.
On September 14, 2024 Sean O'Malley met Merab Dvalishvili in a bantamweight (UFC Championship) title defense fight. O'Malley was 29 years old and with a record of 18-2 (13), and Dvalishvili was 33 years old and with a record of 17-4 (4). O'Malley lost the fight via 5-round unanimous decision and lost the title.
On August 15, 2020 Sean O'Malley faced off against Marlon Vera in a bantamweight bout at age 25. He was coming in with a record of 12-1 (9), and Vera was 27 years old and with a record of 17-6-1 (15). O'Malley lost the fight via 1st-round TKO.