| Name | Functions | Event Dates | Events | Resources  | ||
|---|---|---|---|---|---|---|
| Martin Oscàr | Actor | 1914 | 1 | |||
| Hans Olsen | Actor | 1902 - 1903 | 17 | |||
| Janusz Orliński | Actor | 1903 - 1909 | 4 | |||
| Marta Ozoliņa | Actor | 1903 | 1 | |||
| Elita Proctor Otis | Actor | 1903 | 13 | |||
| Nance O'Neil | Actor | 1900 - 1917 | 23 | |||
| Helen Ormbee | Actor | 1904 | 1 | |||
| Jane Oaker | Actor | 1904 | 1 | |||
| Kathleen O'Neill | Actor | 1904 | 1 | |||
| Władysława Ordonówna | Actor | 1904 | 1 | |||
| Edith Otis | Actor | 1905 | 1 | |||
| Sava Ognjanov | Actor, Director | 1905 - 1928 | 8 | |||
| Piero Ottolini | Translator | 1905 - 1906 | 4 | |||
| Leo Orlandini | Actor | 1892 - 1924 | 12 | |||
| Paul Orleneff | Actor | 1906 - 1912 | 7 | |||
| Edyth Olive | Actor | 1906 | 1 | |||
| Walter Orchowski | Actor | 1906 | 1 | |||
| Ole Onsøjen | Musical Director | 1906 | 1 | |||
| Clara Osmond | Actor | 1906 - 1907 | 3 | |||
| Pál Olasz | Actor | 1906 - 1908 | 4 | |||
| Bronisław Oranowski | Actor, Translator | 1907 - 1911 | 3 | |||
| Warner Oland | Actor | 1906 - 1908 | 5 | |||
| Antonina Ogińska | Actor | 1908 - 1910 | 3 | |||
| William Owen | Actor | 1908 | 1 | |||
| Barry O'Neil | Director | 1909 | 1 | |||
| Kaoru Osanai | Director | 1909 - 1928 | 6 | |||
| Saburonosuke Okada | Designer | 1909 | 1 | |||
| Zhivko Odzhakov | Actor | 1910 | 1 | |||
| Todor Obreschkov | Actor | 1910 | 1 | |||
| Jurija Odzhakova | Actor | 1910 | 1 | |||
| Franciszka Ostrowska | Actor | 1910 | 2 | |||
| Gunnar Olram | Actor | 1943 - 2006 | 187 | |||
| Bodil Ousdal | Choreographer | 1985 - 1991 | 6 | |||
| Dag Eirik Orbakk | Actor | 1985 | 2 | |||
| Knut Opperud | Designer | 1994 | 1 | |||
| Ragnar Olason | Actor | 1956 - 1973 | 48 | |||
| Elin Osjord | Actor | 1991 | 1 | |||
| Rigmor Ottesen | Actor | 1992 - 2007 | 32 | |||
| Per Ottesen | Actor | 1992 - 2013 | 36 | |||
| Marit Pedersen Omland | Actor | 1993 | 6 | |||
| Arvid Ones | Actor, Director | 1983 - 2004 | 22 | |||
| Dean O'Neill | Actor | 1993 | 1 | |||