| Associate Players | Associate Players | 1922 | 2 | |
| Arts Theatre Club | Arts Theatre Club | 1930 – 1931 | 6 | |
| Artcraft Photoplay | Artcraft Photoplay | 1918 | 1 | |
| Amsterdamsch Lyrisch Tooneel | Amsterdamsch Lyrisch Tooneel | 1902 | 1 | |
| Athens Festival | Athens Festival | 2006 – 2010 | 2 | |
| Arendalsuka | Arendalsuka | 2013 | 1 | |
| Associazione Culturale 'Gianni Santuccio' | Associazione Culturale 'Gianni Santuccio' | 2000 – 2020 | 5 | |
| August Rasmussens Teaterselskab | August Rasmussens Teaterselskab | 1876 – 1878 | 16 | |
| Albert u. Else Bassermann | Albert u. Else Bassermann | 1933 – 1950 | 13 | |
| Alfredo B. Crevenna | Alfredo B. Crevenna | 1954 | 2 | |
| Agnes Sorma und die Irving Place Theatergesellschaft, N.Y. | Agnes Sorma und die Irving Place Theatergesellschaft, N.Y. | 1898 | 1 | |
| Askø Artist | Askø Artist | 2010 | 1 | |
| AGADU | AGADU | 1999 | 1 | |
| Australian Elizabethan Theatre Trust, The | The Australian Elizabethan Theatre Trust | 1970 | 3 | |
| August Sandberg Sällskap | August Sandberg Sällskap | 1878 – 1880 | 5 | |
| ARW Prosjektteater | ARW Prosjektteater | 2006 | 4 | |
| Assitej World Congres | Assitej World Congres | 1999 | 1 | |
| Adelaide Repertory Theatre Incorporated | Adelaide Repertory Theatre Incorporated | 1917 – 1964 | 3 | |
| Aesthetic Realism Theatre Company, The | The Aesthetic Realism Theatre Company | 2001 | 2 | |
| Adelaide Festival of Arts | Adelaide Festival of Arts | 2006 | 1 | |
| American Conservatory Theater | American Conservatory Theater | 1973 – 2007 | 8 | |
| Association Franco-Norvégienne | Association Franco-Norvégienne | 1929 | 1 | |
| Afternoon Theatre, The | The Afternoon Theatre | 1909 | 2 | |
| Abbey Theatre | Abbey Theatre | 2005 – 2011 | 3 | 1 |
| Agder Teater | Agder Teater | 1993 – 2015 | 70 | 7 |
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