Carlton is a census-designated place in Missoula County, Montana, United States. The population was 721 at the 2020 census. Carlton is in southern Missoula County in western Montana, in the northern part of the Bitterroot Valley. The southern border of the community follows the Ravalli County line. U.S. Route 93 passes through the community, leading north 17 …Carlton is a census-designated place in Missoula County, Montana, United States. The population was 721 at the 2020 census. Carlton is in southern Missoula County in western Montana, in the northern part of the Bitterroot Valley. The southern border of the community follows the Ravalli County line. U.S. Route 93 passes through the community, leading north 17 miles to Missoula and south 30 miles to Hamilton. The post office that covers the CDP is in Florence, 3 miles south of Carlton.