Thompson is a town in Windham County, Connecticut, United States. The town is part of the Northeastern Connecticut Planning Region. The town was named after Sir Robert Thompson, an English landholder. The population was 9,189 at the 2020 census. Thompson is located in the northeastern corner of the state and is bordered on the north by Web…Thompson is a town in Windham County, Connecticut, United States. The town is part of the Northeastern Connecticut Planning Region. The town was named after Sir Robert Thompson, an English landholder. The population was 9,189 at the 2020 census. Thompson is located in the northeastern corner of the state and is bordered on the north by Webster, Massachusetts and Dudley, Massachusetts, on the east by Douglas, Massachusetts and Burrillville, Rhode Island, on the west by Woodstock, Connecticut, and on the south by Putnam, Connecticut.