Vergennes is a city located in the northwest quadrant of Addison County, Vermont, United States. The municipality is bordered by the towns of …Vergennes is a city located in the northwest quadrant of Addison County, Vermont, United States. The municipality is bordered by the towns of Ferrisburgh, Panton, and Waltham. As of the 2020 census, its population was 2,553. It is the smallest of Vermont's 10 cities in terms of population, though the city of Winooski has the smallest area. It was the first city chartered in the state of Vermont and is the only city in Addison County.