Colchester is a town in New London County, Connecticut, United States. The population was 16,068 at the 2010 census. In 2010 Colchester became the first town in Connecticut, and the 36th in the country, to be certified with the National Wildlife Federation as a Community Wildlife Habitat.Colchester is one of the fastest growing towns in Connecticut. The villages of Westchester and North Westchester are located within Colchester. The town center village, which was previously incorporated as a borough, is a census-designated place, with a population of 4,781 at the 2010 census.The Colchester Historical Society operates a local history museum in town.