| Itzehoe | Itzehoe | Germany, Itzehoe | 2002-09-26 | -- | 2002 | 1 | |
| Ibsenparken | Ibsenparken | Norway, Skien | 2006-05-23 | -- | 2006 | 1 | |
| Ineu | Ineu | Romania, Ineu | -- | -- | | | |
| 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 | |
| Ila skole | Ila skole | Norway, Oslo, Fougstads gate 10 | 2005-11-04 | -- | 2005 | 1 | |
| Irish Theatre, The | The Irish Theatre | Ireland, Dublin | 1917-04-23 | 1918-02-09 | 1917–1918 | 2 | |
| Instituto Andrés Soler (ANDA) | Instituto Andrés Soler (ANDA) | Mexico, Mexico City, Petén 45, Narvarte Poniente | 2000-10-14 | -- | 2000 | 1 | |
| India | India | India | 1940-- | -- | 1940–2020 | 4 | |
| Italy | Italy | Italy, Italy | 1918-01- | 1980-03-24 | 1918–2021 | 19 | |
| Industrial Strength Theatre | Industrial Strength Theatre | United States of America, Herndon, 269 Sunset Park Dr | 2008-01-25 | 2008-02-16 | 2008 | 1 | |
| Incognito Theatre | Incognito Theatre | England, Friern Barnet, London, Holly Park Road | 2005-02-08 | 2012-12-01 | 2005–2012 | 2 | |
| Illinois Theatre | Illinois Theatre | United States of America, Rock Island | 1904-03-15 | 1904-03-15 | 1904 | 1 | |
| Irondale Center | Irondale Center | United States of America, Brooklyn, 85 South Oxford Street | 2022-10-05 | 2022-11-20 | 2022 | 1 | |
| Isala Theater | Isala Theater | Netherlands, Capelle aan Den IJssel, Stadsplein 5 | 2009-12-22 | -- | 2009–2013 | 2 | |
| Industrial space | Industrial Space | United States of America, New York, Chelsea | 1994-08- | 1995-11- | 1994 | 2 | |
| Imperial Theatre | Imperial Theatre | England, Westminster, London, Tothill Street | 1903-01-25 | 1903-01-26 | 1903 | 2 | |
| Idrettshallen | Idrettshallen | Norway, Sogndal, Lunnamyri 4 | 1971-10-22 | 1997-10-13 | 1971–1997 | 2 | |
| Idrettshuset | Idrettshuset | Norway, Straumsnes | 1956-02-08 | -- | 1956–1963 | 3 | |
| Iontas Theatre | Iontas Theatre | Ireland, Castleblayney Co, Monaghan, Conabury | 2007-03-09 | -- | 2007 | 1 | |
| IJmuiden Stadsschouwburg | IJmuiden Stadsschouwburg | Netherlands, Velsen, Stadsschouwburg Velsen | 2002-12-14 | -- | 2002–2003 | 2 | |
| Ingebrigt Davik-huset | Ingebrigt Davik-huset | Norway, Brattvåg, Bernt Hildrevegen 2 | 2011-04-28 | 2014-04-01 | 2011–2014 | 2 | |
| Ileana | Ileana | Romania, Ileana | -- | -- | | | |
| Ibsen Theatre | Ibsen Theatre | United States of America, New York | 1935-04-01 | -- | 1935 | 1 | |
| International Festival of Monodrama - Die Pumpe | International Festival of Monodrama - Die Pumpe | Germany, Kiel | 2006-11-11 | -- | 2006 | 1 | |
| Idrettshallen, Risør | Risør idrettshall | Norway, Risør | 1975-03-17 | -- | 1975 | 1 | |
| Ireland | Ireland | Ireland | 1980-01-29 | 1980-04-19 | 1980 | 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 | |
| IOGT-huset | IOGT-huset | Norway, Bergen, Sverresgate 1 | 1990-02-08 | 1990-02-14 | 1990 | 1 | |
| Irkutskij dramatičeskij teatr | Irkutskij dramatičeskij teatr (Irkutsk Drama Theatre) | Russia, Irkutsk | 1946-- | -- | 1946 | 1 | |
| Ingeborg-Drewitz-Bibliothek | Ingeborg-Drewitz-Bibliothek | Germany | 2023-08-31 | 2023-08-31 | 2023 | 1 | |
| Ibsenhuset | Ibsenhuset | Norway, Skien, Lundegata 6 | 1973-09-07 | 2024-04-25 | 1973–2024 | 39 | |
| Irving Greenberg Theatre Centre | Irving Greenberg Theatre Centre | Canada, Ottawa, 1233 Wellington Street West | 2009-03-10 | 2009-03-21 | 2009 | 1 | |
| Inderøy Kulturhus | Inderøy Kulturhus | Norway, Sakshaug | 1993-03-11 | -- | 1993 | 1 | |
| Izmail | Izmail | Ukraine, Izmail | -- | -- | | | |
| Illnau-Effretikon ZH | Illnau-Effretikon ZH | Switzerland | 2002-11-16 | -- | 2002 | 1 | |
| Ibsenmuseet | Ibsenmuseet | Norway, Oslo, Henrik Ibsens gate 26 | 2002-10-02 | 2003-10-26 | 2002–2012 | 6 | |
| 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 | |
| Interzona | Interzona | Italy, Verona, Via Santa Teresa, 6 | 1999-10-07 | -- | 1999 | 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 | |
| Innsjön | Innsjön | Sweden, Innsjön | 1911-07-03 | 1911-07-04 | 1911 | 1 | |
| International Theatre | International Theatre | United States of America, New York | 1946-11-12 | 1947-02-19 | 1946 | 1 | |
| Iranshahr | Iranshahr | Iran, Tehran, Artists' Park, Iranshahr St. | 2020-02-16 | 2020-03-16 | 2020 | 1 | |
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