Colebrook is a town in Litchfield County, Connecticut, United States. The population was 1,361 at the 2020 census. The town is part of the Northwest Hills Planning Region. Colebrook was named after Colebrooke in the English county of Devon; the reason is now unknown.

Litchfield County is in northwestern Connecticut, United States. As of the 2020 census, the population was 185,186. The county was named after Lichfield, in England. Litchfield County has the lowest population density of any county in Connecticut and is the state's largest county by area.