Terryville is a census-designated place (CDP) in Litchfield County, Connecticut, United States, and is the largest village within the town of Plymouth. As of the 2020 census, Terryville had a population of 5,202. The village is named for Eli Terry Jr., the son of the well-known clockmaker Eli Terry Sr.. Terryville is also home to the Lock Museum of America. There is a water wheel located in downtown Terryville that is dedicated to the son of Eli Terry Sr.