Littleton is a home rule municipality city located in Arapahoe, Douglas, and Jefferson counties, Colorado, United States. Littleton is the county seat of Arapahoe County and is a part of the Denver–Aurora–Lakewood, CO Metropolitan Statistical Area. The city population was 45,652 at the 2020 United States Census, ranking as the 20th most populous municipality in the State of Colorado.

Arapahoe County is a county located in the U.S. state of Colorado. As of the 2020 census, its population was 655,070, making it the third-most populous county in Colorado. The county seat is Littleton, and the most populous city is Aurora. The county was named for the Arapaho Native American tribe, who once lived in the region.