Lupac (Romanian: Lupac; Croatian: Lupak; ) is a commune in Caras-Severin County, Romania. In 2002, its population numbered 3,023 people and was mostly made up of Krashovani Croats. It is composed of four villages: Clocotici (Klokotic; Krassócsörgo), Lupac, Rafnic (Ravnik; Kengyeltó) and Vodnic (Vodnik; Vizes).