Lyme is a town along the Connecticut River in Grafton County, New Hampshire, United States. The population was 1,745 as of the 2020 census. Lyme is home to the Chaffee Natural Conservation Area. The Dartmouth Skiway is in the eastern part of town, near the village of Lyme Center. The Appalachian Trail passes through the town's heavily wooded eastern end.

Grafton County is a county in the U.S. state of New Hampshire. As of the 2020 census, the population was 91,118. Its county seat is the town of Haverhill. In 1972, the county courthouse and other offices were moved from Woodsville, a larger village within the town of Haverhill, to North Haverhill.