Asotin was derived from a Nez Perce Native American language term meaning "eel creek." It was established in 1878 by Alexander Sumpster and platted in 1881. In those early years, there were two Asotins in the region – Assotin City, located on the southern portion of present-day Asotin, and the town of Asotin, just to the north. By 1883, Asotin had outgrown its southern counterpart, and in 1886, the two merged as the single community of Asotin.