| Name | Functions | Event Dates | Events | Resources  | ||
|---|---|---|---|---|---|---|
| Júlíus Oddsson | Actor | 1944 | 1 | |||
| Peter Orban | Lighting Designer | 2011 | 8 | |||
| Heinrich Oppermann | Actor | 1895 - 1925 | 13 | |||
| Teresina Oster | Actor | 1906 - 1909 | 4 | |||
| Ben Ormerod | Lighting Designer | 1994 - 2007 | 41 | |||
| James O'Reilly | Actor | 1981 | 2 | |||
| Alessia Olivetti | Actor | 2008 - 2011 | 4 | |||
| Ole Andreas Olsen | Actor | 1859 | 1 | |||
| Frk. Olsen | Actor | 1874 - 1876 | 5 | |||
| Julius Olbrich | Actor | 1876 - 1910 | 16 | |||
| Rosa Otto-Martineck | Actor | 1876 | 1 | |||
| - Olsen | Actor | 1883 | 1 | |||
| Hans Leonard Ottomeyer | Actor | 1878 | 1 | |||
| Erik Ohlsson | Actor | 1878 - 1883 | 8 | |||
| Herr Otto | Actor, Director | 1878 | 2 | |||
| Mr. Oppmar | Actor | 1879 | 1 | |||
| Van Offel-Kley | Actor | 1880 | 1 | |||
| Jacques Offenbach | Composer | 1880 | 1 | |||
| Charles Oberthür | Composer | 1880 | 1 | |||
| - Ohlson | Actor | 1882 | 1 | |||
| Adolf Otremba | Translator | 1882 - 1883 | 3 | |||
| Julia Otrembowa | Actor, Translator | 1883 - 1899 | 4 | |||
| Ludvig Otterström | Actor | 1883 - 1885 | 10 | |||
| Rasmus Ottesen | Actor | 1902 - 1926 | 18 | |||
| Mr. Olsson | Actor | 1886 | 1 | |||
| - Olander | Actor | 1887 | 1 | |||
| Anna Oeser | Actor | 1888 | 1 | |||
| Pēteris Ozoliņš | Actor, Director | 1889 - 1912 | 5 | |||
| Mr. Ott | Actor | 1889 | 2 | |||
| Thomas Oberle | Actor | 1891 - 1904 | 2 | |||
| J. L. Ottomeyer | Actor | 1891 | 1 | |||
| Teodor Olchowny | Actor | 1891 | 1 | |||
| Stanisław Olszewski | Actor | 1892 | 1 | |||
| Irmgard Olbrich | Actor | 1893 - 1901 | 2 | |||
| Mr. Onorato | Actor | 1893 | 2 | |||
| Albert Olander | Actor | 1893 | 2 | |||
| Hermann Orlop | Actor | 1893 | 1 | |||
| Georg Oppel | Actor | 1893 - 1926 | 9 | |||
| Fritz Odemar | Actor, Director | 1893 - 1934 | 5 | |||
| Edward Olszewski | Actor | 1894 - 1902 | 3 | |||
| Otto Oßmann | Actor | 1894 | 1 | |||
| O. Orling | Designer | 1895 | 2 | |||