| India | India | India | 1940-- | -- | 1940–2020 | 4 | |
| Il Torrione | Il Torrione | Italy, Città di Castello, via Gramsci 28 | 2011-06-23 | -- | 2011 | 1 | |
| Ibsenhuset | Ibsenhuset | Norway, Skien, Lundegata 6 | 1973-09-07 | 2024-04-25 | 1973–2024 | 39 | |
| Irondale Center | Irondale Center | United States of America, Brooklyn, 85 South Oxford Street | 2022-10-05 | 2022-11-20 | 2022 | 1 | |
| Inner Stage, The, University of Guelph | The Inner Stage, University of Guelph | Canada, Guelph, 50 Stone Road East | 1990-11-25 | 1990-12-01 | 1990 | 1 | |
| Ishøj Centersal | Ishøj Centersal | Denmark, Ishøj | 2002-11-15 | -- | 2002–2004 | 2 | |
| Ianca | Ianca | Romania, Ianca | -- | -- | | | |
| Inderøy Kulturhus | Inderøy Kulturhus | Norway, Sakshaug | 1993-03-11 | -- | 1993 | 1 | |
| ILAII - Artes escénicas | ILAII - Artes escénicas | Mexico, Mérida | 2024-08-30 | 2024-08-31 | 2024 | 1 | |
| IATC Studio Cassandra | IATC Studio Cassandra | Romania, Bucharest, Str. Matei Voievod nr. 75-77 | 1957-03-15 | -- | 1957–1985 | 4 | |
| Ida Aalbergin kiertue | Ida Aalbergin kiertue | Finland | -- | -- | | | |
| Ibsenmuseet | Ibsenmuseet | Norway, Oslo, Henrik Ibsens gate 26 | 2002-10-02 | 2003-10-26 | 2002–2012 | 6 | |
| Interimstheater Brünn | Interimstheater Brünn | Czech Republic, Brno, Žerotín square | 1880-01-01 | -- | 1880 | 1 | |
| Interzona | Interzona | Italy, Verona, Via Santa Teresa, 6 | 1999-10-07 | -- | 1999 | 1 | |
| International Theatre of Tehran | International Theatre of Tehran | Iran, Tehran | 1970-- | -- | 1970 | 1 | |
| Innsjön | Innsjön | Sweden, Innsjön | 1911-07-03 | 1911-07-04 | 1911 | 1 | |
| Iran | Iran | Iran, Iran | 1993-02-03 | -- | 1993–2017 | 3 | |
| 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 | |
| Incognito Theatre | Incognito Theatre | England, Friern Barnet, London, Holly Park Road | 2005-02-08 | 2012-12-01 | 2005–2012 | 2 | |
| Istropolitana MDPOH | Istropolitana MDPOH | Slovak Republic, Bratislava, Ventúrska 3 | 2012-06-26 | -- | 2012 | 1 | |
| Intimiteatteri | Intimiteatteri | Finland, Helsinki, Ratakatu 9 | 1951-03-28 | -- | 1951–1962 | 3 | |
| Imperial Theatre | Imperial Theatre | United States of America, New York, 249 W 45th St | 1924-05-01 | -- | 1924 | 1 | |
| Ingeborg-Drewitz-Bibliothek | Ingeborg-Drewitz-Bibliothek | Germany | 2023-08-31 | 2023-08-31 | 2023 | 1 | |
| Industrial space | Industrial Space | United States of America, New York, Chelsea | 1994-08- | 1995-11- | 1994 | 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 of America, Ithaca, Ithaca College | 1952-02-28 | 1952-03-01 | 1952 | 1 | |
| Isbjørnhallen | Isbjørnhallen | Norway, Hammerfest, Meridiangata 8 | 1997-11-05 | 1997-11-06 | 1997 | 1 | |
| Islamabad | Islamabad | Pakistan, Islamabad | 2006-05-17 | -- | 2006 | 1 | |
| Intimes Theater | Intimes Theater | Germany, Nürnberg, Wolfsschlucht | 1901-01-03 | -- | 1901–1912 | 7 | |
| Istindportalen | Istindportalen | Norway, Heggelia, Kapellveien 2 | 2007-03-12 | -- | 2007 | 1 | |
| Ibestad Samfunnshus | Ibestad Samfunnshus | Norway, Hamnvik, 9450 Hamnvik | 1970-02-28 | -- | 1970 | 1 | |
| Ironwood Opera House | Ironwood Opera House | United States of America, Ironwood | 1899-02-24 | 1899-02-24 | 1899 | 1 | |
| Iberoamericano de Teatro de Bogotá | Iberoamericano de Teatro de Bogotá | Colombia, Bogotá, Cundinamarca, Carrera 19 # 37-53 | 2008-03-07 | 2008-03-10 | 2008 | 1 | |
| Iranshahr | Iranshahr | Iran, Tehran, Artists' Park, Iranshahr St. | 2020-02-16 | 2020-03-16 | 2020 | 1 | |
| Iranian Artists Forum, Entezami Hall | Iranian Artists Forum, Entezami Hall | Iran, Tehran, Iranshahr Street, Boostan Honarmandan | 2018-02-23 | 2023-07-11 | 2018–2023 | 2 | |
| Island Arts Centre | Island Arts Centre | Northern Ireland, Lisburn, Lagan Valley Island | 2011-04-11 | -- | 2011–2018 | 2 | |
| Immenstadt | Immenstadt | Germany, Immenstadt | -- | -- | | | |
| IBSEN Museum & Teater | IBSEN Museum & Teater | Norway, Oslo, Henrik Ibsens gate 26 | 2022-03-20 | 2022-06-12 | 2022 | 2 | |
| IOGT-huset | IOGT-huset | Norway, Bergen, Sverresgate 1 | 1990-02-08 | 1990-02-14 | 1990 | 1 | |
| Itzehoe | Itzehoe | Germany, Itzehoe | 2002-09-26 | -- | 2002 | 1 | |
| Ineu | Ineu | Romania, Ineu | -- | -- | | | |
| Ivano-Frankivsk | Ivano-Frankivsk | Ukraine, Ivano-Frankivsk | 1907-03- | 1907-04- | 1907 | 1 | |
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