Flathead (or Salish ) Indians, a North American tribe of the Salishan language family. They called themselves Se'lic, meaning “people,” from which the name Salish is derived. They were called Flatheads by neighboring tribes that deformed their own heads into a conical shape; the Flatheads had normally shaped heads. They lived in western Montana around Flathead Lake, and were originally fishermen and, later, hunters. By a treaty in 1855, the Flatheads surrendered all their land except an area south of Flathead Lake, which became their reservation. Today more than 72,000 Flatheads live in the United States and in Canada.