| Orth, Franz | Franz Orth | Actor | 2007 | 3 | |
| Ouellette, Jean-Sébastien | Jean-Sébastien Ouellette | Actor | 2009 - 2022 | 3 | 1 |
| O'Neill, Michelle | Michelle O'Neill | Actor | 2008 | 3 | |
| Olt, Edgar | Edgar Olt | Actor | 1955 | 3 | |
| Ono, Y. | Y. Ono | Dramaturg | 2008 - 2009 | 3 | |
| Ott, Karl | Karl Ott | Actor | 1880 - 1893 | 3 | |
| Ono, Hacchaku | Hacchaku Ono | Dramaturg | 2009 | 3 | |
| Oblokar, Samo | Samo Oblokar | Lighting Designer | 2010 - 2012 | 3 | |
| Obst, Angela | Angela Obst | Dramaturg | 2012 - 2021 | 3 | |
| O'Mahony, Paul | Paul O'Mahony | Designer | 2013 - 2017 | 3 | |
| Ohlsson, Fredrik | Fredrik Ohlsson | Actor | 1957 | 3 | |
| Oosterwijk, Nora | Nora Oosterwijk | Actor | 1956 - 1957 | 3 | |
| Orendy, C. | C. Orendy | Actor | 1920 - 1928 | 3 | |
| Okkola, Helena | Helena Okkola | Actor | 1998 | 3 | |
| O’Hearn, Robert | Robert O’Hearn | Actor, Designer | 1949 - 1950 | 3 | |
| Oates, Cicely | Cicely Oates | Actor | 1930 | 3 | |
| Orbeck, Anders | Anders Orbeck | Translator | 1936 - 2018 | 3 | 1 |
| Otero, Cachi | Cachi Otero | Costume Designer | 1971 | 3 | |
| Olson, Niclas | Niclas Olson | Actor, Adaptation, Director | 2017 | 3 | |
| Olivero, Franco | Franco Olivero | Actor | 1986 - 1987 | 3 | |
| Orléans, Sabine | Sabine Orléans | Actor | 1994 | 3 | |
| Ovanessian, Arby | Arby Ovanessian | Costume Designer, Designer, Director | 1970 | 3 | 1 |
| Omar, Hersh | Hersh Omar | Musician | 2013 - 2014 | 3 | |
| Orlando, Carlo | Carlo Orlando | Assistant Director | 2021 | 3 | |
| Ortenzi, Oriana | Oriana Ortenzi | Actor | 2022 - 2024 | 3 | |
| Olding, Francesca | Francesca Olding | Actor | 1980 | 3 | |
| Olding, Federico | Federico Olding | Actor | 1980 | 3 | |
| Obinu, Gianfranco Onatziro | Gianfranco Onatziro Obinu | Actor | 2015 - 2019 | 3 | |
| Orozco, Pablo | Pablo Orozco | Actor | 2024 | 3 | |
| Ohland, Hans | Hans Ohland | Costume Designer, Designer | 1963 - 1981 | 4 | |
| Olsson, Lennart | Lennart Olsson | Director | 1971 - 1987 | 4 | 1 |
| Orchis, Isella | Isella Orchis | Actor | 1993 - 2013 | 4 | |
| Orlik, Stanisław | Stanisław Orlik | Actor | 1904 - 1924 | 4 | |
| Outin, Régis | Régis Outin | Actor | 1928 - 1978 | 4 | 1 |
| Owen, Marianne | Marianne Owen | Actor | 1978 - 1996 | 4 | |
| Oest, Johann Adam | Johann Adam Oest | Actor | 1977 - 2004 | 4 | 1 |
| Ottenheimer, Albert M. | Albert M. Ottenheimer | Actor | 1932 - 1936 | 4 | |
| Opsvig, Virginia | Virginia Opsvig | Costume Designer, Mask Maker | 1931 - 1936 | 4 | |
| Oster, Teresina | Teresina Oster | Actor | 1906 - 1909 | 4 | |
| Olivetti, Alessia | Alessia Olivetti | Actor | 2008 - 2011 | 4 | |
| Otrembowa, Julia | Julia Otrembowa | Actor, Translator | 1883 - 1899 | 4 | |
| Olin, Vilhelm | Vilhelm Olin | Actor, Director | 1886 - 1919 | 4 | 1 |
|
|
