Combattants Etats-Unis
| 1926 |  | Oluwale Bamgbose | 1-4-0 UFC | #3619 |  |
| 1927 |  | Omoyele Gonzalez | 0-1-0 REC | #5848 | |
| 1928 |  | Orion Cosce | 1-2-0 UFC | #3977 | |
| 1929 |  | Orlando Sanders | 0-1-0 REC | #7573 | |
| 1930 |  | Oscar Jurado Sanchez | 2-0-0 REC | #255 | |
| 1931 |  | Oseyiomon Oiyemhonlan | 1-2-0 REC | #4758 | |
| 1932 |  | Ovince St. Preux | 15-13-0 UFC | #274 | |
| 1933 |  | Ozzy Diaz | 1-2-0 UFC | #1443 | |
| 1934 |  | Pablo Garza | 3-3-0 UFC | #3165 | |
| 1935 |  | Paige VanZant | 5-4-0 UFC | #1770 | |
| 1936 |  | Pam Sorenson | 0-2-0 REC | #5424 | |
| 1937 |  | Paris Moran | #8092 | | |
| 1938 |  | Parker Porter | 4-4-0 UFC | #2451 | |
| 1939 |  | Pat Audinwood | 0-2-0 UFC | #5541 | |
| 1940 |  | Pat Barry | 5-7-0 UFC | #2071 | |
| 1941 |  | Pat Downey | 1-1-0 REC | #4660 | |
| 1942 |  | Pat Healy | 0-5-0, 1NC UFC | #2962 | |
| 1943 |  | Pat Miletich | 8-2-0 UFC | #335 | |
| 1944 |  | Pat Sabatini | 9-2-0 UFC | #268 | |
| 1945 |  | Pat Schilling | 0-2-0 UFC | #4304 | |
| 1946 |  | Patchy Mix | 0-2-0 UFC | #1475 | |
| 1947 |  | Patrick Brady | 0-1-0 REC | #7551 | |
| 1948 |  | Patrick Cornett | 0-1-0 REC | #6951 | |
| 1949 |  | Patrick Cummins | 6-7-0 UFC | #1783 | |
| 1950 |  | Patrick Rivera | #8129 | |