| Oglesby, Ben | Ben Oglesby | Actor | 2013 | 1 | |
| Osborne, Collin | Collin Osborne | Actor | 2013 | 1 | |
| O'Mahony, Paul | Paul O'Mahony | Designer | 2013 - 2017 | 3 | |
| O'Byrne, Peter | Peter O'Byrne | Actor | 2013 | 1 | |
| O'Dea, Donncha | Donncha O'Dea | Actor | 2013 | 1 | |
| O'Donoghue, James | James O'Donoghue | Actor | 2013 | 1 | |
| Osbourne, Jessica | Jessica Osbourne | Director | 2013 | 1 | |
| Olsen, Oliver | Oliver Olsen | Costume Designer | 1959 | 2 | |
| Oliver, Norman | Norman Oliver | Actor | 1959 | 2 | |
| Ojeda, Oscar | Oscar Ojeda | Actor | 2013 | 1 | |
| Ogborn, Jane | Jane Ogborn | Actor | 1959 | 1 | |
| Okano, Kazuo | Kazuo Okano | Translator | 1959 | 1 | |
| O'Dea, Maureen | Maureen O'Dea | Actor | 1959 | 1 | |
| Opsahl, Arve | Arve Opsahl | Actor | 1958 | 1 | |
| Obermeier, Hermann | Hermann Obermeier | Actor | 1958 | 1 | |
| Olafsdottir, Karin | Karin Olafsdottir | Actor | 1957 | 1 | |
| Olsson, Jöran | Jöran Olsson | Actor | 1957 | 1 | |
| Ohlsson, Fredrik | Fredrik Ohlsson | Actor | 1957 | 3 | |
| O'Sullivan IV, John | John O'Sullivan IV | Actor | 2013 | 1 | |
| Obradovic, Daniel | Daniel Obradovic | Actor | 1956 | 1 | |
| Olsen, Jens-Anker | Jens-Anker Olsen | Designer | 1954 - 1956 | 2 | |
| Olinescu, Boris | Boris Olinescu | Actor, Assistant Director | 1959 | 2 | |
| Overhoff, Ilde | Ilde Overhoff | Actor | 1956 | 1 | |
| Orozco, Hiram Alexander | Hiram Alexander Orozco | Costume Designer | 2016 | 1 | |
| Olteanu, Smaragda | Smaragda Olteanu | Actor | 1983 | 1 | |
| Owen, Tony | Tony Owen | Designer | 2013 | 1 | |
| Olaru, Ion | Ion Olaru | Actor | 1970 | 1 | |
| Ovaska, Sulo | Sulo Ovaska | Actor, Designer | 1956 | 2 | |
| Orlikowsky, Wazlaw | Wazlaw Orlikowsky | Adaptation, Choreographer, Director | 1956 | 3 | |
| Oosterwijk, Nora | Nora Oosterwijk | Actor | 1956 - 1957 | 3 | |
| Ophaug, Erna | Erna Ophaug | Sound Designer | 1953 - 2006 | 4 | |
| Omdal, Leif | Leif Omdal | Actor | 1935 - 1956 | 4 | |
| Ohki, Yasushi | Yasushi Ohki | Director | 1955 - 1956 | 2 | |
| Odekerken, Michel | Michel Odekerken | Actor | 1954 | 1 | |
| Oh, Natsuki | Natsuki Oh | Actor | 1998 | 1 | |
| Oyamada, Akira | Akira Oyamada | Sound Designer | 1998 | 1 | |
| Olsen, Mikkel, Are | Mikkel Are Olsen | Dancer | 2006 | 1 | |
| Ockermüller, Heinz | Heinz Ockermüller | Designer | 1953 | 1 | |
| Okakura, Shiro | Shiro Okakura | Director | 1953 | 1 | |
| Ohmori, Yoshio | Yoshio Ohmori | Actor | 1953 | 1 | |
| Ohmachi, Fumio | Fumio Ohmachi | Actor | 1953 | 1 | |
| Orendy, C. | C. Orendy | Actor | 1920 - 1928 | 3 | |
|
|
