Underbool is a town situated on the section of the Mallee Highway between Ouyen and the South Australian border in the Sunraysia region. The place by road, is situated about kilometres west from Torrita and kilometres east from Linga. At the 2006 census, Underbool had a population of 217.
The town name is thought to come from the German word underbolt given to it by surveyor Dr Neumayer when he camped there in October, 1861.
The town services the grain farmers and graziers in the area. For tourists it provides access to the Pink Lakes in Murray-Sunset National Park.