Sells is a census-designated place (CDP) in Pima County, Arizona, United States. The population was 2,799 at the 2000 census. It is the capital of the Tohono O'odham Nation and the home of several of their tribal businesses, such as Tohono O'Odham Ki:Ki Association. Originally known as Indian Oasis, the settlement took its present English name in 1918 to honor Indian Commissioner Cato Sells. The O'odham name means "Tortoise Got Wedged".