| Dore O. | Work | Biography | Bibliography | Characteristics |
| Wendy Oberlander | Work | Biography | Bibliography | Characteristics |
| Vaughn Obern | Work | Biography | Bibliography | Characteristics |
| George Obremski | Work | Biography | Bibliography | Characteristics |
| Marcel Odenbach | Work | Biography | Bibliography | Characteristics |
| Odin Teatret | Work | Biography | Bibliography | Characteristics |
| Nobuhiko Ohbayashi | Work | Biography | Bibliography | Characteristics |
| Jenny Okun | Work | Biography | Bibliography | Characteristics |
| Pat O'Neill | Work | Biography | Bibliography | Characteristics |
| Yoko Ono | Work | Biography | Bibliography | Characteristics |
| Dennis Oppenheim | Work | Biography | Bibliography | Characteristics |
| Michael O'Reilly | Work | Biography | Bibliography | Characteristics |
| Jerry Orr | Work | Biography | Bibliography | Characteristics |
| Steve Osborn | Work | Biography | Bibliography | Characteristics |
| Vivian Ostrovsky | Work | Biography | Bibliography | Characteristics |
| Philip Ostrow | Work | Biography | Bibliography | Characteristics |
| Tony Oursler | Work | Biography | Bibliography | Characteristics |
| Edward Owens | Work | Biography | Bibliography | Characteristics |
| Kyo Ozawa | Work | Biography | Bibliography | Characteristics |