Poston is an unincorporated community and census-designated place (CDP) in La Paz County, Arizona, United States, in the Parker Valley. The population was 285 at the 2010 census, down from 389 in 2000.
During World War II, Poston was the site of the Poston War Relocation Center, one of the United States' largest Japanese-American internment camps, where over 17,000 Japanese-Americans were held over a three-year period. The camp sites are now home to a monument dedicated to those interned there.
Poston is located in western La Paz County, in the Parker Valley at (33.990348, -114.401052). It is east of the Colorado River, which forms the state border with California. Mohave Road runs through the community, leading north to Parker and south to Ehrenberg. The community lies within the boundaries of the Colorado River Indian Reservation.
According to the United States Census Bureau, the Poston CDP has a total area of , all land.
As of the