| 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 | |
| Ibsenparken | Ibsenparken | Norway, Skien | 2006-05-23 | -- | 2006 | 1 | |
| Istropolitana MDPOH | Istropolitana MDPOH | Slovak Republic, Bratislava, Ventúrska 3 | 2012-06-26 | -- | 2012 | 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 | |
| Ingeborg-Drewitz-Bibliothek | Ingeborg-Drewitz-Bibliothek | Germany | 2023-08-31 | 2023-08-31 | 2023 | 1 | |
| Irish Theatre, The | The Irish Theatre | Ireland, Dublin | 1917-04-23 | 1918-02-09 | 1917–1918 | 2 | |
| Intimiteatteri | Intimiteatteri | Finland, Helsinki | 1951-03-28 | -- | 1951–1962 | 3 | |
| Ithaca College Little Theatre | Ithaca College Little Theatre | United States of America, Ithaca, Ithaca College | 1952-02-28 | 1952-03-01 | 1952 | 1 | |
| Italy | Italy | Italy, Italy | 1918-01- | -- | 1918–1986 | 16 | |
| Il Piccolo Teatro Instabile | Il Piccolo Teatro Instabile | Italy, Turin, via Garessio 18 | 2004-04-24 | -- | 2004 | 1 | |
| Incognito Theatre | Incognito Theatre | England, Friern Barnet, London, Holly Park Road | 2005-02-08 | 2012-12-01 | 2005–2012 | 2 | |
| Islamabad | Islamabad | Pakistan, Islamabad | 2006-05-17 | -- | 2006 | 1 | |
| Industrial space | Industrial Space | United States of America, New York, Chelsea | 1994-08- | 1995-11- | 1994 | 2 | |
| Intimes Theater | Intimes Theater | Germany, Nürnberg, Wolfsschlucht | 1901-01-03 | -- | 1901–1912 | 7 | |
| Imperial Theatre | Imperial Theatre | England, Westminster, London, Tothill Street | 1903-01-25 | 1903-01-26 | 1903 | 2 | |
| Iranshahr | Iranshahr | Iran, Tehran, Artists' Park, Iranshahr St. | 2020-02-16 | 2020-03-16 | 2020 | 1 | |
| Idrettshallen | Idrettshallen | Norway, Sogndal, Lunnamyri 4 | 1971-10-22 | 1997-10-13 | 1971–1997 | 2 | |
| Ironwood Opera House | Ironwood Opera House | United States of America, Ironwood | 1899-02-24 | 1899-02-24 | 1899 | 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 | |
| Iontas Theatre | Iontas Theatre | Ireland, Castleblayney Co, Monaghan, Conabury | 2007-03-09 | -- | 2007 | 1 | |
| IBSEN Museum & Teater | IBSEN Museum & Teater | Norway, Oslo, Henrik Ibsens gate 26 | 2022-03-20 | 2022-06-12 | 2022 | 2 | |
| Ingebrigt Davik-huset | Ingebrigt Davik-huset | Norway, Brattvåg, Bernt Hildrevegen 2 | 2011-04-28 | 2014-04-01 | 2011–2014 | 2 | |
| Island Arts Centre | Island Arts Centre | Northern Ireland, Lisburn, Lagan Valley Island | 2011-04-11 | -- | 2011–2018 | 2 | |
| Ibsen Theatre | Ibsen Theatre | United States of America, New York | 1935-04-01 | -- | 1935 | 1 | |
| Itzehoe | Itzehoe | Germany, Itzehoe | 2002-09-26 | -- | 2002 | 1 | |
| Idrettshallen, Risør | Risør idrettshall | Norway, Risør | 1975-03-17 | -- | 1975 | 1 | |
| Ineu | Ineu | Romania, Ineu | -- | -- | | | |
| Instituto Andrés Soler (ANDA) | Instituto Andrés Soler (ANDA) | Mexico, Mexico City, Petén 45, Narvarte Poniente | 2000-10-14 | -- | 2000 | 1 | |
| Ibsenhuset | Ibsenhuset | Norway, Skien, Lundegata 6 | 1973-09-07 | 2020-09-01 | 1973–2022 | 38 | |
| Ila skole | Ila skole | Norway, Oslo, Fougstads gate 10 | 2005-11-04 | -- | 2005 | 1 | |
| IOGT-huset | IOGT-huset | Norway, Bergen, Sverresgate 1 | 1990-02-08 | 1990-02-14 | 1990 | 1 | |
| Inderøy Kulturhus | Inderøy Kulturhus | Norway, Sakshaug | 1993-03-11 | -- | 1993 | 1 | |
| Industrial Strength Theatre | Industrial Strength Theatre | United States of America, Herndon, 269 Sunset Park Dr | 2008-01-25 | 2008-02-16 | 2008 | 1 | |
| Illinois Theatre | Illinois Theatre | United States of America, Rock Island | 1904-03-15 | 1904-03-15 | 1904 | 1 | |
| Île-Saint-Louis-Paul Rey, Théâtre de l' | Théâtre de l'Île-Saint-Louis-Paul Rey | France, Paris, 39 quai d'Anjou | 2009-04-21 | 2009-05-24 | 2009 | 1 | |
| Ibsenmuseet | Ibsenmuseet | Norway, Oslo, Henrik Ibsens gate 26 | 2002-10-02 | 2003-10-26 | 2002–2012 | 6 | |
| Isala Theater | Isala Theater | Netherlands, Capelle aan Den IJssel, Stadsplein 5 | 2009-12-22 | -- | 2009–2013 | 2 | |
| Interzona | Interzona | Italy, Verona, Via Santa Teresa, 6 | 1999-10-07 | -- | 1999 | 1 | |
| Instituto Português do Desporto e da Juventude | Instituto Português do Desporto e da Juventude | Portugal, Lisbon | 2023-06-05 | 2023-06-05 | 2023 | 1 | |
| Innsjön | Innsjön | Sweden, Innsjön | 1911-07-03 | 1911-07-04 | 1911 | 1 | |
| Idrettshuset | Idrettshuset | Norway, Straumsnes | 1956-02-08 | -- | 1956–1963 | 3 | |
| Iran | Iran | Iran, Iran | 1993-02-03 | -- | 1993–2017 | 3 | |
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