Moore County is a county located in the U.S. state of Texas. As of the 2020 census, its population was 21,358. The county seat is Dumas. The county was created in 1876 and organized in 1892. It is named for Edwin Ward Moore, the commander of the Texas Navy. The Dumas micropolitan statistical area includes all of Moore County.

Dumas is a city and the county seat of Moore County, Texas, United States. The population was 14,501 at the 2020 census. Located approximately 40 miles north of Amarillo, the city is named for its founder, Louis Dumas (1856–1923). Dumas Avenue, the main thoroughfare, is also United States Highways 87 and 287.