Vukovar-Syrmia county (Croatian: Vukovarsko-srijemska županija) is the easternmost Croatian county. It includes the eastern parts of Slavonia and western parts of Srijem regions; but also the lower Sava river basin (Posavina).

County seat is Vukovar, on Danube river; and the biggest town is Vinkovci with 33,328 inhabitans. The whole county has 204,768 inhabitans. Other towns include Ilok and Županja.