or
Player positions provided by the CFL and errors are known to exist
| Name | Position | Regular GP | # of Seasons (Years) | Also played for |
|---|---|---|---|---|
| O'Billovich, Bob | DB, HB | 69 | 5 (1963–1967) | |
| O'Brien, Danny | QB | 45 | 3 (2014–2016) | BC, EDM |
| O'Connor, Pete | E | 12 | 4 (1937–1940) | |
| O'Doherty, Bob | WR | 1 | 1 (1979) | WPG |
| Ogilvie, Emerson | HB | 12 | 3 (1930–1932) | |
| Okeke, Uzooma | T | 14 | 1 (1996) | MTL, SHR |
| Oldham, Hugh | WR | 68 | 5 (1970–1974) | |
| Oliver, Frank | DB | 5 | 1 (1980) | BC |
| Oliver, Jimmy Jr. | WR | 18 | 1 (2002) | BC, TOR |
| O'Malley, Tom | P, QB | 38 | 3 (1951–1953) | |
| Omara, Ron | LB | 8 | 1 (2017) | BC, HAM |
| O'Neil, Stan | FW, HB | 32 | 6 (1935–1940) | |
| Onyeka, Kene | DL | 6 | 1 (2019) | |
| Oramasionwu, Don | DL | 0 | 1 (2018) | EDM, MTL, WPG |
| Orange, Anthony | DB | 2 | 1 (2017) | BC, EDM, TOR |
| Ordway, Jonathan | DB | 21 | 2 (2003–2004) | |
| Organ, Gerry | K, WR | 186 | 12 (1971–1977, 1979–1983) | |
| Outley, David | DB | 1 | 1 (1985) | |
| Oxley, Anthony | FB | 4 | 1 (1994) | |
| Ozarko, Mike | T | 18 | 2 (1945–1946) | HAM, OTTC |
| “O” player count: 20 | ||||