Hailing from Montana, USA, Sean Daniel O'Malley, born on October 24, 1994, is an American bantamweight MMA fighter (135 lbs) of the Ultimate Fighting Championship (UFC). As of May 2025, he is ranked #1 in the bantamweight division. O'Malley fights out of Glendale, Arizona, and trains at The MMA Lab under the guidance of head trainer John Crouch. He receives coaching from his longtime friend and training partner, Tim Welch.
During the early stages of his MMA fighting career in Montana, O'Malley earned himself the nickname "Sugar" from one of his fighting coaches. O'Malley fought his first 5 matches in Montana. Later, he moved to North Dakota and eventually joined the Legacy Fighting Alliance, where he gained attention for his impressive knockout win over David Nuzzo. Following his victory against Nuzzo, O'Malley's performance earned him a spot on Dana White's Contender Series 2. In this event, he faced Alfred Khashakyan and secured a remarkable first-round KO, which led to him being offered a contract to fight in the UFC.
Sean O'Malley's weight class
Sean O’Malley fights in the bantamweight division of the UFC, where the weight limit is 135 lbs or 61 kg. Considered a flamboyant fighter in the division, O'Malley defeated Aljamain Sterling at UFC 292 to become the new UFC bantamweight champion and also defended the title once against Marlon Vera.
O’Malley has also fought one fight in the flyweight division in his MMA career. This fight was against Mark Coates at Intense Championship Fighting 23 on November 7, 2015. O’Malley won the bout via a unanimous decision.
Sean O’Malley’s MMA record
Sean O'Malley has a professional mixed martial arts record of 18 wins, 2 losses, and 1 no-contest to his name as of May 2025.
| Result | Record | Opponent | Method | Event | Date | Round | Time | Location |
| Loss | 18-2 | Merab Dvalishvili | Decision (unanimous) | UFC 316 | September 14, 2024 | 5 | 5:00 | Las Vegas, Nevada, United States |
| Win | 18-1 | Marlon Vera | Decision (unanimous) | UFC 299 | March 9, 2024 | 5 | 5:00 | Miami, Florida, United States |
| Win | 17-1 | Aljamain Sterling | TKO | UFC 292 | August 19, 2023 | 2 | 0:51 | Boston, Massachusetts, USA |
| Win | 16–1 (1) | Petr Yan | Decision (split) | UFC 280 | October 22, 2022 | 3 | 5:00 | Abu Dhabi, United Arab Emirates |
| NC | 15–1 (1) | Pedro Munhoz | NC (accidental eye poke) | UFC 276 | July 2, 2022 | 2 | 1:51 | Las Vegas, Nevada, United States |
| Win | 15–1 | Raulian Paiva | TKO (punches) | UFC 269 | December 11, 2021 | 1 | 4:42 | Las Vegas, Nevada, United States |
| Win | 14–1 | Kris Moutinho | TKO (punches) | UFC 264 | July 10, 2021 | 3 | 4:33 | Las Vegas, Nevada, United States |
| Win | 13–1 | Thomas Almeida | KO (punch) | UFC 260 | March 27, 2021 | 3 | 3:52 | Las Vegas, Nevada, United States |
| Loss | 12–1 | Marlon Vera | TKO (elbows and punches) | UFC 252 | August 16, 2020 | 1 | 4:40 | Las Vegas, Nevada, United States |
| Win | 12–0 | Eddie Wineland | KO (punch) | UFC 250 | June 6, 2020 | 1 | 1:54 | Las Vegas, Nevada, United States |
| Win | 11–0 | José Alberto Quiñónez | TKO (head kick and punches) | UFC 248 | March 7, 2020 | 1 | 2:02 | Las Vegas, Nevada, United States |
| Win | 10–0 | Andre Soukhamthath | Decision (unanimous) | UFC 222 | March 3, 2018 | 3 | 5:00 | Las Vegas, Nevada, United States |
| Win | 9–0 | Terrion Ware | Decision (unanimous) | The Ultimate Fighter: A New World Champion Finale | December 1, 2017 | 3 | 5:00 | Las Vegas, Nevada, United States |
| Win | 8–0 | Alfred Khashakyan | KO (punch) | Dana White's Contender Series 2 | July 18, 2017 | 1 | 4:14 | Las Vegas, Nevada, United States |
| Win | 7–0 | David Nuzzo | KO (spinning wheel kick) | LFA 11 | May 5, 2017 | 1 | 2:15 | Phoenix, Arizona, United States |
| Win | 6–0 | Irvin Veloz | KO (punch) | EB: Beatdown 20 | March 18, 2017 | 1 | 2:34 | New Town, North Dakota, United States |
| Win | 5–0 | Tycen Lynn | KO (head kick) | Intense Championship Fighting 26 | October 21, 2016 | 2 | 2:57 | Great Falls, Montana, United States |
| Win | 4–0 | Mark Coates | Decision (unanimous) | Intense Championship Fighting 23 | November 7, 2015 | 3 | 5:00 | Helena, Montana, United States |
| Win | 3–0 | Omar Avelar | Submission (rear-naked choke) | Intense Championship Fighting 20 | August 21, 2015 | 1 | 2:55 | Great Falls, Montana, United States |
| Win | 2–0 | Shane Sargent | KO (punch) | Intense Championship Fighting 19 | July 3, 2015 | 1 | 2:03 | Choteau, Montana, United States |
| Win | 1–0 | Josh Reyes | TKO (punches) | Intense Championship Fighting 17 | March 6, 2015 | 1 | 1:33 | Great Falls, Montana, United States |
Related: What is sean o malleys ufc record?
FAQs on Sean O'Malley Weight Class
A. Sean ‘Sugar’ O’Malley fights in the bantamweight division of the Ultimate Fighting Championship.
A. Sean O’Malley weighs 135 lbs, which is the upper limit to fight in the bantamweight division.
A. Currently, Merab Dvalishvili is the champion of the bantamweight division in UFC.
A. Sean O’Malley is 5 feet 11 inches (1.80m) tall.
A. Yes, O’Malley secured a victory against Petr Yan via a split decision, although the decision was highly controversial.
