Here is a list of O'Malley's best fights. For a list of O'Malley's losses, refer to "Sean O'Malley Losses".
On August 19, 2023 Sean O'Malley fought Aljamain Sterling in a bantamweight title fight for Sterling's UFC Championship title. O'Malley was 28 years old and with a record of 17-1 (13), and Sterling was 34 years old and with a record of 23-3 (11). O'Malley stopped Aljamain Sterling via 2nd-round TKO and is crowned the new UFC bantamweight champion.
On March 9, 2024 Sean O'Malley met Marlon Vera in a bantamweight (UFC Championship) title defense fight. O'Malley was 29 years old and with a record of 18-1 (13), and Vera was 31 years old and with a record of 23-8-1 (18). O'Malley won the fight via 5-round unanimous decision and successfully defended his title.
On June 6, 2020 Sean O'Malley faced off against Eddie Wineland in a bantamweight bout at age 25. He was coming in with a record of 12-0 (9), and Wineland was 35 years old and with a record of 24-13-1 (19). O'Malley stopped Eddie Wineland via KO.
On December 11, 2021 Sean O'Malley faced off against Raulian Paiva in a bantamweight bout at age 27. He was coming in with a record of 15-1 (12), and Paiva was 26 years old and with a record of 21-3 (7). O'Malley stopped Raulian Paiva via TKO.
On March 27, 2021 Sean O'Malley faced off against Thomas Almeida in a bantamweight bout at age 26. He was coming in with a record of 13-1 (10), and Almeida was 29 years old and with a record of 22-4 (21). O'Malley stopped Thomas Almeida via KO.
On March 7, 2020 Sean O'Malley faced off against José Alberto Quiñónez in a bantamweight bout at age 25. He was coming in with a record of 11-0 (8). O'Malley stopped José Alberto Quiñónez via TKO.
On July 10, 2021 Sean O'Malley faced off against Kris Moutinho in a bantamweight bout at age 26. He was coming in with a record of 14-1 (11). O'Malley stopped Kris Moutinho via TKO.
On March 3, 2018 Sean O'Malley faced off against Andre Soukhamthath in a bantamweight bout at age 23. He was coming in with a record of 10-0 (7), and Soukhamthath was 29 years old and with a record of 12-5 (11). O'Malley won the fight via 3-round unanimous decision.
On October 22, 2022 Sean O'Malley faced off against Petr Yan in a bantamweight bout at age 27. He was coming in with a record of 16-1 (12), and Yan was 29 years old and with a record of 16-3 (8). O'Malley won the fight via 3-round split decision.
On December 1, 2017 Sean O'Malley faced off against Terrion Ware in a bantamweight bout at age 23. He was coming in with a record of 9-0 (7), and Ware was 31 years old and with a record of 17-6 (9). O'Malley won the fight via 3-round unanimous decision.