Groton is a town located on the Thames River in New London County, Connecticut, United States. The population was 39,907 at the 2000 census. Groton is the home of the Electric Boat Corporation, which is the major contractor for submarine work for the United States Navy, and the Navy's SUBASE New London. The pharmaceutical company Pfizer is also a major employer. The Avery Point section of Groton is home to a regional campus of the University of Connecticut.