Sorted alphabetically by last name · 2769 fighters
| Name | Nickname | |
|---|---|---|
| KM | Keith Mielke | |
| KR | Keith Rockel | "Rock" |
| KW | Keith Wisniewski | "The Polish Connection" |
| KD | Kelly Dullanty | "Psycho" |
| KF | Kelly Faszholz | |
| KG | Kelvin Gastelum | |
| KS | Ken Shamrock | "The World's Most Dangerous Man" |
| KS |
| Ken Stone |
| KG | Kendall Grove | "Da Spyder" |
| KY | Kenichi Yamamoto |