Londonderry is a town in Windham County, Vermont, United States. It is bounded on the north by Landgrove and Weston, on the east by Windham, on the south by Jamaica and on the west by Winhall and Landgrove. Londonderry also includes the village of South Londonderry. According to the United States Census Bureau, the town has a total area of 35.9 square miles (92.9 square kilometers), of which, 35.7 square miles (92.4 square kilometers) of it is land and 0.2 square miles (0.5 square kilometers) of it (0.59%) is water. The West River flows through the town.