| Instituto Andrés Soler (ANDA) | Instituto Andrés Soler (ANDA) | Mexico, Mexico City, Petén 45, Narvarte Poniente | 2000-10-14 | -- | 2000 | 1 | |
| Instituto Municipal de Educación | Instituto Municipal de Educación | Spain, Madrid, Calle de Mejía Lequerica, 21 | 1963-10-27 | -- | 1963 | 1 | |
| Istanbul | Istanbul | Turkey, Istanbul | 1900-12- | 2014-05-29 | 1900–2014 | 5 | |
| Impossible Ragtime Theater | Impossible Ragtime Theater | United States, New York | 1979-01-28 | -- | 1979 | 1 | |
| IATC Studio Cassandra | IATC Studio Cassandra | Romania, Bucharest, Str. Matei Voievod nr. 75-77 | 1957-03-15 | -- | 1957–1985 | 4 | |
| Interimstheater Brünn | Interimstheater Brünn | Czech Republic, Brno, Žerotín square | 1880-01-01 | -- | 1880 | 1 | |
| Illinois Theatre | Illinois Theatre | United States, Rock Island | 1904-03-15 | 1904-03-15 | 1904 | 1 | |
| Innsbruck | Innsbruck | Austria, Innsbruck | 1946-04-27 | 1946-04-28 | 1946 | 1 | |
| Ipswich | Ipswich | England, Ipswich | -- | -- | | | |
| Istropolitana MDPOH | Istropolitana MDPOH | Slovak Republic, Bratislava, Ventúrska 3 | 2012-06-26 | -- | 2012 | 1 | |
| Idrettshallen | Idrettshallen | Norway, Kautokeino | 1997-10-31 | -- | 1997 | 1 | |
| Inntunet | Inntunet | Norway, Vinstra, Vinstra | 2006-08-07 | -- | 2006 | 1 | |
| Intimiteatteri | Intimiteatteri | Finland, Helsinki | 1951-03-28 | -- | 1951–1962 | 3 | |
| Iranian Artists Forum, Entezami Hall | Iranian Artists Forum, Entezami Hall | Iran, Tehran, Iranshahr Street, Boostan Honarmandan | 2018-02-23 | 2018-02-25 | 2018 | 1 | |
| Intiman Theatre | Intiman Theatre | United States, Seattle, 201 Mercer Street | 1996-12-08 | 2012-08-25 | 1996–2012 | 4 | |
| Illinois Theatre | Illinois Theatre | United States, Chicago, 65 E. Jackson Boulevard | 1908-01-31 | -- | 1908–1927 | 2 | |
| Il Piccolo Teatro Instabile | Il Piccolo Teatro Instabile | Italy, Turin, via Garessio 18 | 2004-04-24 | -- | 2004 | 1 | |
| Ithaca College Little Theatre | Ithaca College Little Theatre | United States, Ithaca, Ithaca College | 1952-02-28 | 1952-03-01 | 1952 | 1 | |
| ITA ensemble | ITA ensemble | Netherlands, Amsterdam, Leidseplein 26 | 2021-11-05 | 2021-11-13 | 2021 | 1 | |
| Islamabad | Islamabad | Pakistan, Islamabad | 2006-05-17 | -- | 2006 | 1 | |
| Ireland | Ireland | Ireland | 1980-01-29 | 1980-04-19 | 1980 | 1 | |
| Iðnó | Iðnó | Iceland, Reykjavík | 1932-11-24 | -- | 1932–1943 | 2 | |
| Iitti | Iitti | Finland, Iitti | -- | -- | | | |
| Ironwood Opera House | Ironwood Opera House | United States, Ironwood | 1899-02-24 | 1899-02-24 | 1899 | 1 | |
| Irkutskij dramatičeski teatr | Irkutskij dramatičeski teatr | Russia, Irkutsk | 1946-- | -- | 1946 | 1 | |
| Izmir | Izmir | Turkey, Izmir | 1903-11- | 2013-05- | 1903–2012 | 2 | |
| Idrettsbygget | Idrettsbygget | Norway, Løkken Verk | 1969-09-17 | -- | 1969 | 2 | |
| Island Arts Centre | Island Arts Centre | Northern Ireland, Lisburn, Lagan Valley Island | 2011-04-11 | -- | 2011–2018 | 2 | |
| Inderøy kulturhus | Inderøy kulturhus | Norway, Inderøy, Vennalivegen 15 | 2001-06-25 | -- | 2001–2006 | 2 | |
| Ila fengsel | Ila fengsel | Norway, Eiksmarka, Jøssingveien 33 | 2012-11-28 | -- | 2012 | 2 | |
| Itzehoe | Itzehoe | Germany, Itzehoe | 2002-09-26 | -- | 2002 | 1 | |
| Ineu | Ineu | Romania, Ineu | -- | -- | | | |
| India | India | India | 1940-- | -- | 1940–1991 | 3 | |
| Irving Place Theatre | Irving Place Theatre | United States, New York, East 15th Street | 1897-04-12 | 1913-11-12 | 1897–1918 | 9 | |
| International Theatre | International Theatre | United States, New York | 1946-11-12 | 1947-02-19 | 1946 | 1 | |
| Irondale Center | Irondale Center | United States, Brooklyn, 85 South Oxford Street | 2022-10-05 | 2022-11-20 | 2022 | 1 | |
| Independent Theatre | Independent Theatre | Australia, North Sydney, 271 Miller Street | 1946-10-10 | -- | 1946–1951 | 2 | |
| Intiman, Malmö Stadsteater | Intiman, Malmö Stadsteater | Sweden, Malmö, Östra Rönneholmsvägen 20 | 1954-10-08 | 2015-04-29 | 1954–2015 | 11 | |
| Ila skole | Ila skole | Norway, Oslo, Fougstads gate 10 | 2005-11-04 | -- | 2005 | 1 | |
| Industrial Strength Theatre | Industrial Strength Theatre | United States, Herndon, 269 Sunset Park Dr | 2008-01-25 | 2008-02-16 | 2008 | 1 | |
| Imperial Theatre | Imperial Theatre | Canada, Vancouver | 1908-07-09 | 1908-07-09 | 1908 | 1 | |
| Intimes Theater | Intimes Theater | Switzerland, Bern | 1909-10-21 | 1909-12-01 | 1909 | 1 | |
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