| Subcategories | | O'Brien, Conan | O'Brien, Edmond | O'Brien, Logan | O'Brien, Margaret | O'Brien, Mariah | O'Brien, Pat |
| O'Brien, Richard | O'Brien, Tina | O'Connell, Jerry | O'Connor, Carroll | O'Connor, Donald | O'Connor, Frances |
| O'Connor, Glynnis | O'Connor, Renee | O'Dell, Jennifer | O'Donnell, Chris | O'Donnell, Rosie | O'Grady, Gail |
| O'Hanlon, Ardal | O'Hara, Catherine | O'Hara, Maureen | O'Hare, Michael | O'Keefe, Jodi Lyn | O'Keefe, Michael |
| O'Keeffe, Douglas | O'Keeffe, Miles | O'Leary, Matt | O'Mearain, Lochlann | O'Neal, Ryan | O'Neal, Tatum |
| O'Neill, Ed | O'Quinn, Terry@ | O'Rourke, Heather | O'Toole, Peter | Oberoi, Vivek@ | Oh, Sandra@ |
| Ohama, Natsuko | Ohmart, Carol | Oldfield, Mike@ | Oldman, Gary | Oleynik, Larisa | Olin, Lena |
| Oliver, Christian | Olivier, Laurence | Olmos, Edward James | Olsen, Mary-Kate and Ashley | Olson, Heather Lauren | Olyphant, Timothy |
| Omundson, Tim | Ono, Yoko@ | Ophüls, Max@ | Orange, Jason | Orbach, Jerry | Oreiro, Natalia |
| Ormond, Julia | Orr, Ashley Rose@ | Orrico, Laura | Ortiz, Scarlet | Osbourne, Jack | Osbourne, Ozzy@ |
| Osment, Haley Joel | Osmond, Donny | Oteri, Cheri | Otto, Barry | Otto, Miranda | Ousmane, Sembène@ |
| Outhwaite, Tamzin | Overton, Rick | Owen, Chris | Owen, Clive | Owens, Chris | Owens, Gary@ |
| Oxenberg, Catherine | Oÿ, Jenna von@ |
