This is the list of all people with a lastname starting with "O" that we currently track in the category Celebrities.
| Margaret O'Brien | Rosie O'Donnell | Paige O'Hara |
| Alex O'Loughlin | Ryan O'Neal | Gary Oldman |
| Laurence Olivier | Ashley Olsen | Ozzy Osbourne |
| Frank Oz | Tatum O’Neal |