Casey O'Neill (11-2, 5) was born in Irvine, Scotland on October 7, 1997. At the age of 21 years on April 5, 2019, she made her professional MMA debut against Amira Hafizović, winning the fight via 5-round unanimous decision.
On February 20, 2021, 23-year old Casey O'Neill made her UFC debut on her 6th professional MMA fight at UFC Fight Night: Blaydes vs. Lewis against a 31-year old Shana Dobson, winning the fight in the 2nd round via TKO.
O'Neill's last fight was a 1st-round KO win against Gabriella Fernandes at UFC Fight Night: Adesanya vs. Pyfer at age 28 on March 28, 2026. She is on a 2-fight winning streak.
She has fought eight times in the UFC, and has a record of 6 wins and 2 losses in the promotion.
Some of Casey O'Neill's best fights have been against Shana Dobson, Gabriella Fernandes, Antonina Shevchenko, Lara Procópio, Luana Santos and Roxanne Modafferi. For details about these fights refer to "Best fights of Casey O'Neill".
O'Neill has 2 losses on her MMA record. For details about these losses refer to "Casey O'Neill Losses".
| # | Date | Opponent | Promotion | Weight | Round | Method | Result |
|---|---|---|---|---|---|---|---|
13 | Mar 28, 2026 28 years, 5 months 11-2 (5) | Gabriella Fernandes | UFC | FL | 1 | KO | Win Punches |
12 | Aug 18, 2024 26 years, 10 months 10-2 (4) | Luana Santos | UFC | FL | 3 | UD | Win |
11 | Dec 16, 2023 26 years, 2 months 9-2 (4) | Ariane Lipski | UFC | FL | 2 | SUB | Loss Armbar |
10  | Mar 18, 2023 25 years, 5 months 9-1 (4) | 34 years, 5 months 20-9-1 (9) | UFC | FL | 3 | UD | Loss |
9  | Feb 12, 2022 24 years, 4 months 9-0 (4) | 39 years, 4 months 25-19 (9) | UFC | FL | 3 | SD | Win |
8  | Oct 2, 2021 23 years, 11 months 8-0 (4) | 36 years, 10 months 9-3 (3) | UFC | FL | 2 | TKO | Win Punches |
7  | Jun 19, 2021 23 years, 8 months 7-0 (3) | 25 years, 7 months 7-1 (3) | UFC | FL | 3 | CKO | Win Rear-naked choke |
6  | Feb 20, 2021 23 years, 4 months 6-0 (3) | 31 years, 10 months 4-4 (2) | UFC | FL | 2 | TKO | Win Punches |
5 | Sep 25, 2020 22 years, 11 months 5-0 (2) | Christina Stelliou | FL | 2 | KO | Win Punches | |
4 | Feb 29, 2020 22 years, 4 months 4-0 (1) | Caitlin McEwen | FL | 3 | UD | Win | |
3 | Oct 4, 2019 21 years, 11 months 3-0 (1) | Miki Motono | ST | 5 | UD | Win | |
2 | Jul 27, 2019 21 years, 9 months 2-0 (1) | Jada Ketley | ST | 1 | SUB | Win Rear-naked choke | |
1 | Apr 5, 2019 21 years, 5 months 1-0 (0) | Amira Hafizović | ST | 5 | UD | Win |
