Underbool is a town in the Mallee region of north-west Victoria, Australia. The town is in the Rural City of Mildura local government area and on the Mallee Highway—between Ouyen and the South Australian border – 476 kilometres (296 mi) north west of the state capital, Melbourne. At the 2006 census, Underbool had a population of 217. The town services the grain farmers and graziers in the area.