Sean O'Malley (fighter)

O'Malley trains in Glendale, Arizona at The MMA Lab led by head trainer John Crouch,[5] and is coached by his long time friend, Tim Welch.[6]

O'Malley was given the nickname "Sugar" by one of his MMA coaches in Montana early on in his career. When O'Malley asked why this nickname was chosen, his coach responded, "Because you're sweet to watch".[6]

O'Malley fought his first five fights of his career in his native Montana, before leaving to fight in North Dakota and eventually fought for Legacy Fighting Alliance where he got a highlight reel knockout over David Nuzzo.[7]

After his win over Nuzzo, O'Malley earned a spot on Dana White's Tuesday Night Contender Series when he took on Alfred Khashakyan. O'Malley beat Khashakyan with a stunning knockout in the first round and was awarded a UFC contract.[8]

O'Malley's promotional debut came against Terrion Ware on December 1, 2017 at The Ultimate Fighter 26 Finale.[9] O'Malley won the fight via unanimous decision.[10]

O'Malley next faced Andre Soukhamthath on March 3, 2018 at UFC 222.[11] He won the fight by unanimous decision, despite injuring his foot in the third round.[12] This fight earned both participants a Fight of the Night bonus.[13]

O'Malley was expected to face José Alberto Quiñónez on October 6, 2018 at UFC 229.[14] However, O'Malley announced that he was out of the fight on September 30 due to a potential Anti-Doping Policy violation.[15] On October 25, O'Malley received hip surgery while waiting to receive judgment pending his potential violation.[16] Subsequently, O'Malley was suspended for six months by the NSAC after testing positive for ostarine. He became eligible to return as of March 2019.[17]

O'Malley was scheduled to face Marlon Vera on July 6, 2019 at UFC 239.[18] However, O'Malley announced his withdrawal from the bout on June 21, 2019 due to a failed test for ostarine. The Nevada State Athletic Commission decided to suspend him due to the failed test and he was suspended for 6 months by USADA. The ostarine in his system was likely residual from his previously failed test prior to UFC 229.[19][20]

O'Malley faced José Alberto Quiñónez at UFC 248 on March 7, 2020.[21] He won the fight via TKO in the first round.[22] This win earned him his first Performance of the Night award.[23]

O'Malley faced former WEC Bantamweight Champion Eddie Wineland at UFC 250 on June 6, 2020.[24] He won the fight via one-punch knockout in the first round.[25] This win earned him the Performance of the Night.[26]

O'Malley faced Marlon Vera in the co-main event of UFC 252 on August 15, 2020.[27] He lost the fight by technical knockout in the first round.[28][29] O'Malley suffered a lower leg injury during the first round of the fight. He would later be diagnosed with drop foot.[30]

O'Malley is scheduled to face Thomas Almeida on March 27, 2021 at UFC 260.[31]

O'Malley competed at Quintet: Ultra as a member of Team UFC on December 12, 2019. He submitted Takanori Gomi with a guillotine choke in his opening round of the tournament but was subsequently submitted by Hector Lombard with an ankle-lock. The team advanced to the next round and faced Team Strikeforce. In that round, he went to a draw with former Strikeforce champion Gilbert Melendez, being both eliminated of the round. Team UFC ended up winning the tournament.[32]

O'Malley also entered the 155lbs Advanced No gi division of Grappling Industries Phoenix on September 20, 2020 and placed third in a seven-man division, only losing to the eventual winner, Robert Degle.[33]

Chael Sonnen put out an open challenge on behalf of O'Malley for his promotion's event on December 20, 2020. The challenge was answered by James Gallagher, who challenged O'Malley to a grappling match at the SUG event. O'Malley reportedly declined the matchup and Gallagher was left without an opponent.[34]