The Vukovar massacre, also known as the Vukovar hospital massacre or the Ovčara massacre, was the killing of Croatian prisoners of war and civilians by Serb paramilitaries, to whom they had been turned over by the Yugoslav People's Army (JNA), at the Ovčara farm southeast of Vukovar on 20 November 1991, during the Croatian War of Independence. The massacre occurred shortly after Vukovar's capture by the JNA, Territorial Defence (TO), and paramilitaries from neighbouring Serbia. It was the largest massacre of the Croatian War of Independence.

The Yugoslav People's Army, also called the Yugoslav National Army, was the military of the Socialist Federal Republic of Yugoslavia and its antecedents from 1945 to 1992.