| Ibsengården | Ibsengården | Norway, Skien, Snipetorp | 2001-08-23 | 2004-08-26 | 2001–2004 | 2 | |
| International Festival of Monodrama - Die Pumpe | International Festival of Monodrama - Die Pumpe | Germany, Kiel | 2006-11-11 | -- | 2006 | 1 | |
| Ireland | Ireland | Ireland | 1980-01-29 | 1980-04-19 | 1980 | 1 | |
| Irkutskij dramatičeskij teatr | Irkutskij dramatičeskij teatr (Irkutsk Drama Theatre) | Russia, Irkutsk | 1946-- | -- | 1946 | 1 | |
| India | India | India | 1940-- | -- | 1940–2020 | 4 | |
| Intimní scéna | Intimní scéna | Czech Republic, Tábor | 1924-12-18 | -- | 1924 | 1 | |
| Intima Teatern | Intima Teatern | Sweden, Stockholm, Barnhusgatan 20 | 1912-11-01 | 1919-03-14 | 1912–1919 | 3 | |
| Irving Greenberg Theatre Centre | Irving Greenberg Theatre Centre | Canada, Ottawa, 1233 Wellington Street West | 2009-03-10 | 2009-03-21 | 2009 | 1 | |
| Izmail | Izmail | Ukraine, Izmail | -- | -- | | | |
| Irondale Center | Irondale Center | United States of America, Brooklyn, 85 South Oxford Street | 2022-10-05 | 2022-11-20 | 2022 | 1 | |
| Istanbul | Istanbul | Turkey, Istanbul | 1900-12- | 2014-05-29 | 1900–2014 | 5 | |
| Ingatestone Hall | Ingatestone Hall | England, Essex, Hall Ln | 2007-09-21 | 2021-07-02 | 2007–2021 | 3 | |
| Ipswich | Ipswich | England, Ipswich | -- | -- | | | |
| Illnau-Effretikon ZH | Illnau-Effretikon ZH | Switzerland | 2002-11-16 | -- | 2002 | 1 | |
| IATC/UNATC ( National University of Theatre and Film "I.L. Caragiale") | IATC/UNATC ( National University of Theatre and Film "I.L. Caragiale" ) | Romania, Bucharest, Matei Voievod Street 75-77 | 1907-05-26 | 1907-05-27 | 1907–2015 | 9 | |
| ILAII - Artes escénicas | ILAII - Artes escénicas | Mexico, Mérida, Calle 13 #94 | 2024-08-30 | 2024-08-31 | 2024 | 1 | |
| Innsbruck | Innsbruck | Austria, Innsbruck | 1946-04-27 | 1946-04-28 | 1946 | 1 | |
| Idrettshallen | Idrettshallen | Norway, Kautokeino | 1997-10-31 | -- | 1997 | 1 | |
| Iowa City Community Theatre | Iowa City Community Theatre | United States of America, Iowa City, 4261 Oak Crest Hill Rd SE | 2005-03-04 | 2005-03-20 | 2005 | 1 | |
| International Theatre | International Theatre | United States of America, New York | 1946-11-12 | 1947-02-19 | 1946 | 1 | |
| Inntunet | Inntunet | Norway, Vinstra, Vinstra | 2006-08-07 | -- | 2006 | 1 | |
| Inkonst | Inkonst | Sweden, Malmö, Bergsgatan 29 | 2006-09-29 | 2006-10-01 | 2006 | 1 | |
| Imperial Theatre | Imperial Theatre | Canada, Vancouver | 1908-07-09 | 1908-07-09 | 1908 | 1 | |
| IGS Garbsen | IGS Garbsen | Germany, Garbsen, Meyenfelder Str. 8, | 2010-10-30 | -- | 2010 | 1 | |
| Institut Méditerranéen des Métiers du Spectacle - IMMS | Institut Méditerranéen des Métiers du Spectacle - IMMS | France, Marseille, 41 rue Jobin | 2017-04-11 | 2017-04-15 | 2017 | 1 | |
| Intiman Theatre | Intiman Theatre | United States of America, Seattle, 201 Mercer Street | 1996-12-08 | 2012-08-25 | 1996–2012 | 4 | |
| Illinois Theatre | Illinois Theatre | United States of America, Chicago, 65 E. Jackson Boulevard | 1908-01-31 | -- | 1908–1927 | 2 | |
| Idavoll | Idavoll | Norway, Ørsta | 1961-01-26 | -- | 1961–1963 | 2 | |
| Ingeborg-Drewitz-Bibliothek | Ingeborg-Drewitz-Bibliothek | Germany | 2023-08-31 | 2023-08-31 | 2023 | 1 | |
| Iðnó | Iðnó | Iceland, Reykjavík | 1932-11-24 | -- | 1932–1943 | 2 | |
| Iitti | Iitti | Finland, Iitti | -- | -- | | | |
| Idrettsbygget | Idrettsbygget | Norway, Løkken Verk | 1969-09-17 | -- | 1969 | 2 | |
| Indiana Repertory Theatre | Indiana Repertory Theatre | United States of America, Indianapolis, 140 W. Washington Street | 2001-01-09 | 2001-02-03 | 2001 | 1 | |
| Idavollen | Idavollen | Norway, Ørstavik | 1952-02-29 | -- | 1952–1956 | 3 | |
| Irish Cultural Center | Irish Cultural Center () | United States of America, Phoenix, North Central Avenue, 1106, Central City | 2025-07-31 | 2025-08-03 | 2025 | 1 | |
| Izmir | Izmir | Turkey, Izmir | 1903-11- | 2013-05- | 1903–2012 | 2 | |
| Inderøy kulturhus | Inderøy kulturhus | Norway, Inderøy, Vennalivegen 15 | 2001-06-25 | -- | 2001–2006 | 2 | |
| International Festival of Monodrama | International Festival of Monodrama | Ukraine, Kiev | 2006-09-23 | -- | 2006 | 1 | |
| Idrettshallen på Tråstad skole | Idrettshallen på Tråstad skole | Norway, Kongsvinger | 1971-09-29 | 1971-09-29 | 1971 | 1 | |
| Instituto LING | Instituto LING | Brazil, Porto Alegre, R. João Caetano, 440 | 2018-05-17 | 2018-05-26 | 2018 | 1 | |
| Iranshahr Theatre | Iranshahr Theatre | Iran, Tehran | 2020-02-16 | 2025-01-21 | 2020–2024 | 2 | |
| Irving Place Theatre | Irving Place Theatre | United States of America, New York, East 15th Street | 1897-04-12 | 1913-11-12 | 1897–1918 | 9 | |
|
|
