| Gender | Male |
|---|---|
| Height | 0' 0" |
| Weight Class | Featherweight |
William Karlsson is a MMA fighter with a amateur fight record of 1 wins, 2 losses and 0 draws
| Amateur Record: | 1-2-0 (Win-Loss-Draw) |
|---|---|
| Career Length | 11 months, 29 days |
| Rounds Fought | 9.0 |
| Avg. Fights/Year | 3.3 |
| Longest Layoff | 8 months, 10 days |
| Quickest Turnaround | 3 months, 19 days |
| Date | Opponent | Weightclass | Method | Round | Time | |||
|---|---|---|---|---|---|---|---|---|
| NSF | 09/13/2025 | L (1-1-0) | Elias Ksia (5-2-0) | FTW | Decision (Split Decision) Fight Club Rush 25 | 3 | 03:00 | |
| NSF | 05/24/2025 | W (0-1-0) | Yousef Jebril (0-0-0) | FTW | Decision (Unanimous Decision) Battle of Botnia: 14 X Fight Club Rush 24 | 3 | 03:00 | |
| NSF | 09/14/2024 | L (0-0-0) | Martin Karlsson (1-1-0) | LW | Decision (Split Decision) Superior Academy 1 | 3 | 03:00 |
| * Bouts marked with an 'Official' logo denote results which have been verified by an ABC-recognized athletic commission * Bouts marked with an (*) are considered exhibition bouts and do not count towards the fighter's record * Weights marked with an (*) denote those over the limit for the weight class |