Plymouth is a town in Litchfield County, Connecticut, United States, located within the Naugatuck Valley Planning Region.

The Terry family participated in a great deal of Plymouth's history.

Eli Terry became partners with Seth Thomas and Silas Hoadley to manufacture clocks in the Greystone section of town.

The Eagle Lock Company closed in the 1970s, and in 1975 the entire abandoned site burned, leaving one building left undamaged.

The Main Street School was located on the green (Baldwin Park) in Terryville.

It was demolished in the 1930s, and the new Terryville High School was constructed behind the green on North Main Street.

The community of Pequabuck is on the eastern border of the town, southeast of Terryville.

[8] Part of Mattatuck State Forest is in the southwest corner of the town.

Route 6 passes through Terryville and Plymouth Center, leading east through Bristol 22 miles (35 km) to Hartford, the state capital, and west through Thomaston, 8 miles (13 km) to Watertown.