The Balkan mixed forests constitute a terrestrial ecoregion of Europe according to both the WWF and Digital Map of European Ecological Regions by the European Environment Agency. It belongs in the Temperate broadleaf and mixed forests Biome and the Palearctic ecozone.
The Balkan mixed forests cover much of the valleys, plains and mountain slopes of the eastern Balkans on different altitudes (except higher parts of the Rhodope and Balkan Mountains, where they are substituted by the Rodope montane mixed forests), extend from approximately the Drina valley to the coasts of the Black, Marmara and Aegean Seas and occupy 224,400 km² (86,600 sq. mi) in Turkey, Greece, the Republic of Macedonia, Bulgaria, Romania, Serbia (Kosovo). The ecoregion is surrounded by the Euxine-Colchic deciduous forests (in Turkey, Georgia and Bulgaria), Aegean and Western Turkey sclerophyllous and mixed forests (in Greece), Pindus Mountains mixed forests (in Greece, the Republic of Macedonia and Albania), Dinaric Mountains mixed forests (in Montenegro and Bosnia and Herzegovina), Pannonian mixed forests (in Bosnia and Herzegovina, Serbia and Romania), Carpathian montane conifer forests, Central European mixed forests (both in Romania), as well as the East European forest steppe and Pontic steppe (both situated in Romania and Bulgaria).