The 2004 Thuringian state election was held on 13 June 2004 to elect the members of the 4th Landtag of Thuringia. The incumbent Christian Democratic Union (CDU) government led by Minister-President Dieter Althaus retained its majority and continued in office.

The Landtag of Thuringia is the parliament of the German federal state of Thuringia. It convenes in Erfurt and currently consists of 90 members from seven parties. According to the free state's constitution, the primary functions of the Landtag are to pass laws, elect the Minister-President and control the government of Thuringia.