O
| Name | Position | College | Years Played |
|---|---|---|---|
| O'Brien, Fran | T | Michigan St. | 1960-66 |
| O'Brien, Gail | T | Nebraska | 1934-36 |
| O'Dell, Stu | LB | Indiana | 1974-77 |
| Ohalete, Ifeanyi | S | USC | 2001-03 |
| Orgin, Pat | DT | Wyoming | 1981-82 |
| Ogunbowale, Dare | RB | Wisconsin | 2017 |
| Okoro, Kenny | CB | Wake Forest | 2014 |
| Oliphant, Mike | RB | Puget Sound | 1988 |
| Oliver, Muhammad | CB | Oregon | 1995 |
| Olkewicz, Neal | LB | Maryland | 1979-89 |
| Olsson, Les | G | Mercer | 1934-38 |
| Olszewski, John | B | California | 1958-60 |
| Orakpo, Brian | DE/LB | Texas | 2009-14 |
| Orr, Terry | TE | Texas | 1986-93 |
| Osborne, Tom | WR | Hastings (NE) | 1960-61 |
| Ostrowski, Chet | E | Notre Dame | 1954-59 |
| Owen, Tom | QB | Wichita St. | 1982 |
| Owens, Brig | DB | Cincinnati | 1966-77 |
| Owens, Don | T | Southern Miss. | 1957 |
| Owens, Rich | DE | Lehigh | 1995-97 |
