The State Archives in Osijek (Croatian: Državni arhiv u Osijeku) is the primary public institution responsible for preservation of archival materials in the Osijek-Baranja County located in Osijek in eastern Croatia. The State Archives in Osijek houses approximately 1,500 collections and archives, totaling over 8,000 linear meters of material and more than 50,000 photographs.

The archive was established after the end of World War II in Yugoslavia in 1947 by the decision of People's Republic of Croatia authorities. In December of 1991, during the Croatian War of Independence, the archive together with other institutions in Croatia was in danger of devastation motivating calls from international scholars for protection.