Lunenburg is a town in Essex County, Vermont, United States. The population was 1,246 at the 2020 census, the most populous in Essex County. Lunenburg contains the villages of Lunenburg and Gilman and hamlets of West Lunenburg, South Lunenburg, and Mill Village, and is part of the Berlin, NH –VT Micropolitan Statistical Area.

Essex County is a county located in the northeastern part of the U.S. state of Vermont. As of the 2020 census, the population was 5,920, making it the least-populous county in both Vermont and New England. Its shire town is the municipality of Guildhall. The county was created in 1792 and organized in 1800. Bordered by the Connecticut River next to New Hampshire, Essex County is south of the Canadian province of Quebec. It is the county with the lowest household-income in Vermont.