Lyndon is a town in Caledonia County, Vermont, United States. As of the 2020 census, the population was 5,491. Lyndon is the home of Lyndon State College. The town contains five unincorporated villages, Lyndonville just east of the geographic center of town, Lyndon Corner in the south, Lyndon Center in the center of town on the west side of Lyndonville, Little Egypt in the north, and East Lyndon in the southeast.

Caledonia County is a county located in the northeastern part of the U.S. state of Vermont. As of the 2020 census, the population was 30,233. Its shire town is the town of St. Johnsbury. The county was created in 1792 and organized in 1796. It was given the Latin name for Scotland, in honor of the many settlers who claimed ancestry there.