• UFC 324(1/24/26) O'Malley won a three round unanimous decision over Song Yadong
• UFC 316(6/7/25) O'Malley was submitted by Merab Dvalishvili via ninja choke at 4:42 of the third round in a fight for the UFC bantamweight title
• UFC 306(9/14/24) O'Malley lost a five round unanimous decision to Merab Dvalishvili, losing the UFC bantamweight title
• UFC 299(3/9/24) O'Malley won a five round unanimous decision over Marlon Vera to retain his UFC bantamweight title
• UFC 292(8/19/23) O'Malley stopped Aljamain Sterling via strikes at :51 of the second round to win the UFC bantamweight title
• UFC 280(10/22/22) O'Malley won a three round split decision over Petr Yan
• UFC 276(7/2/22) O’Malley’s bout with Pedro Munhoz was declared a no contest at 1:51 of the second round when Munhoz was unable to continue after an accidental eye poke
• UFC 269(12/11/21) O’Malley stopped Raulian Paiva via strikes at 4:42 of the first round
• UFC 264(7/10/21) O’Malley stopped Kris Moutinho via strikes at 4:33 of the third round
• UFC 260(3/27/21) O’Malley knocked out Thomas Almeida at 3:52 of the third round
• UFC 252(8/15/20) O’Malley was stopped by Marlon Vera via strikes at 4:40 of the first round
• UFC 250(6/6/20) O’Malley knocked out Eddie Wineland at 1:54 of the first round
• UFC 248(3/7/20) O’Malley stopped Jose Quinonez via strikes at 2:02 of the first round
• UFC 222(3/3/18) O’Malley won a three round unanimous decision over Andre Soukhamthath
• TUF 26 Finale(12/1/17) O’Malley won a three round unanimous decision over Terrion Ware
• Dana White's Contender Series
• Week 2(7/18/17) O’Malley knocked out Alfred Khashakyan at 4:14 of the first round