French River (Massachusetts)  The French River is a river in south-central Massachusetts and northeastern Connecticut, USA. The river rises near Leicester, Massachusetts, and flows generally southwards through Auburn, Oxford, and along the town line between Webster and Dudley; it then enters Connecticut where it joins the Quinebaug River at Thompson, just northeast of Putnam. The Quinebaug in turn flows into the Shetucket River and ultimately the Thames River to empty into the Long Island Sound. The river's total length is , of which are in Massachusetts. It drains a watershed area of about , containing 67 lakes and ponds, 38 of which cover at least . Only one lake in its basin is larger than , namely Lake Chaubunagungamaug (Webster Lake) in Webster, Massachusetts at . French River was so named from a settlement of French Protestants in Oxford.