Tarkio is a city in Tarkio Township, Atchison County, Missouri, United States. The population was 1,583 at the 2010 census . It was platted in 1880 and incorporated in 1881. The name "Tarkio" is from a Native American word meaning "place where walnuts grow". Historically, the economy of the city was based on agriculture and its status as a college town.
Tarkio was founded in 1880, and grew rapidly. The Tarkio Avalanche newspaper was founded in 1884. By 1900, the U.S. Census shows 2,845 persons living in Tarkio. According to the 1910, 1920, and 1930 census, the number of residents held fairly steady for the next 30 years.
One of the community's most famous landmarks was the Tarkio Mule Barn, an octagonal brick structure built in the early 1890s. It was converted to the Tarkio Mule Barn Theatre which was used by Tarkio College. It was on the National Register of Historic Places, but the building was destroyed in a 1989 fire.