Carnes is an unincorporated community in Sioux County, in the U.S. state of Iowa.
A post office was established at Carnes in 1890, and remained in operation until it was discontinued in 1914. The community was named for Edward Carnes, a railroad roadmaster. Carnes' population was 6 in 1902, and 35 in 1925. The population was 13 in 1940.