Osijek is the largest city in the eastern Croatian region of Slavonia and serves as its primary economic and cultural hub. It also functions as the administrative seat of Osijek-Baranja County. As of the 2021 census, it is the fourth-largest city in Croatia with a population of 96,313.
The city is situated on the southern bank of the Drava River at an elevation of 94 meters (308 ft). It is located 25 km upstream from the confluence with the Danube and sits approximately 16 km west of the Croatia–Serbia border.