Tariffville is a neighborhood and census-designated place (CDP) in the town of Simsbury in Hartford County, Connecticut, United States. It is a popular location for whitewater paddlers who use the Farmington River. The population was 1,371 at the 2000 census. The area corresponding to the original mill village is listed as Tariffville Historic District, a historic district listed on the National Register of Historic Places. The historic district excludes newer development around West Point Terrace and Hayes Road, as well as properties along White Water Turn, Wooster Road, and Main Street Extension. The historic district is architecturally significant as a well-preserved example of an early nineteenth century mill village, retaining the old mill housing and street layout.