| Intimes Theater | Intimes Theater | Switzerland, Bern | 1909-10-21 | 1909-12-01 | 1909 | 1 | |
| International Theatre | International Theatre | United States of America, New York | 1946-11-12 | 1947-02-19 | 1946 | 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 | |
| Instituto Municipal de Educación | Instituto Municipal de Educación | Spain, Madrid, Calle de Mejía Lequerica, 21 | 1963-10-27 | -- | 1963 | 1 | |
| Inkonst | Inkonst | Sweden, Malmö, Bergsgatan 29 | 2006-09-29 | 2006-10-01 | 2006 | 1 | |
| Institute of Contemporary Arts (ICA) | Institute of Contemporary Arts (ICA) | England, London, The Mall | 1995-07-04 | 1995-07-08 | 1995 | 1 | |
| Imperial Theatre | Imperial Theatre | Canada, Vancouver | 1908-07-09 | 1908-07-09 | 1908 | 1 | |
| Ibsenparken | Ibsenparken | Norway, Skien | 2006-05-23 | -- | 2006 | 1 | |
| IGS Garbsen | IGS Garbsen | Germany, Garbsen, Meyenfelder Str. 8, | 2010-10-30 | -- | 2010 | 1 | |
| Isthmus Playhouse. Madison Civic Center | Isthmus Playhouse. Madison Civic Center | United States of America, Madison, 201 State Street | 1999-10-22 | 1999-11-14 | 1999 | 1 | |
| Indiana Repertory Theatre | Indiana Repertory Theatre | United States of America, Indianapolis, 140 W. Washington Street | 2001-01-09 | 2001-02-03 | 2001 | 1 | |
| ITA ensemble | ITA ensemble | Netherlands, Amsterdam, Leidseplein 26 | 2021-11-05 | 2021-11-13 | 2021 | 1 | |
| 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 | |
| Imperial Theatre | Imperial Theatre | United States of America, Saint-Louis | 1904-11-17 | 1904-11-17 | 1904 | 1 | |
| Iontas Theatre | Iontas Theatre | Ireland, Castleblayney Co, Monaghan, Conabury | 2007-03-09 | -- | 2007 | 1 | |
| Ibsen Theatre | Ibsen Theatre | United States of America, New York | 1935-04-01 | -- | 1935 | 1 | |
| Idrettshallen, Risør | Risør idrettshall | Norway, Risør | 1975-03-17 | -- | 1975 | 1 | |
| Innsbrucker Kellertheater | Innsbrucker Kellertheater | Austria, Innsbruck, Adolf-Pichler-Platz 8 | 2004-10-20 | 2004-11-30 | 2004 | 1 | |
| International House Theater | International House Theater | United States of America, Chicago | 1934-03-16 | 1934-03-17 | 1934 | 1 | |
| IOGT-huset | IOGT-huset | Norway, Bergen, Sverresgate 1 | 1990-02-08 | 1990-02-14 | 1990 | 1 | |
| Irondale Center | Irondale Center | United States of America, Brooklyn, 85 South Oxford Street | 2022-10-05 | 2022-11-20 | 2022 | 1 | |
| Ismailia Culture Palace Theatre | Ismailia Culture Palace Theatre (قصر ثقافة الإسماعيلية) | Egypt, Ismaïlia | 2006-08-22 | -- | 2006 | 1 | |
| Inderøy Kulturhus | Inderøy Kulturhus | Norway, Sakshaug | 1993-03-11 | -- | 1993 | 1 | |
| Ingensteds | Ingensteds | Norway, Oslo, Brenneriveien 9 | 2014-12-14 | -- | 2014 | 1 | |
| İş Sanat Kültür Merkezi | İş Sanat Kültür Merkezi | Turkey, Levent/İstanbul, İş Kuleleri, Büyükdere Cd., | 2010-02-28 | 2010-05-16 | 2010 | 1 | |
| Interzona | Interzona | Italy, Verona, Via Santa Teresa, 6 | 1999-10-07 | -- | 1999 | 1 | |
| Il Torrione | Il Torrione | Italy, Città di Castello, via Gramsci 28 | 2011-06-23 | -- | 2011 | 1 | |
| Innsjön | Innsjön | Sweden, Innsjön | 1911-07-03 | 1911-07-04 | 1911 | 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 | |
| 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 | |
| Interimstheater Brünn | Interimstheater Brünn | Czech Republic, Brno, Žerotín square | 1880-01-01 | -- | 1880 | 1 | |
| Isbjørnhallen | Isbjørnhallen | Norway, Hammerfest, Meridiangata 8 | 1997-11-05 | 1997-11-06 | 1997 | 1 | |
| International Theatre of Tehran | International Theatre of Tehran | Iran, Tehran | 1970-- | -- | 1970 | 1 | |
| Istropolitana MDPOH | Istropolitana MDPOH | Slovak Republic, Bratislava, Ventúrska 3 | 2012-06-26 | -- | 2012 | 1 | |
| Istindportalen | Istindportalen | Norway, Heggelia, Kapellveien 2 | 2007-03-12 | -- | 2007 | 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 | |
| Ibestad Samfunnshus | Ibestad Samfunnshus | Norway, Hamnvik, 9450 Hamnvik | 1970-02-28 | -- | 1970 | 1 | |
| Iranshahr | Iranshahr | Iran, Tehran, Artists' Park, Iranshahr St. | 2020-02-16 | 2020-03-16 | 2020 | 1 | |
| Il Piccolo Teatro Instabile | Il Piccolo Teatro Instabile | Italy, Turin, via Garessio 18 | 2004-04-24 | -- | 2004 | 1 | |
|
|
