Woodsville is in the northwest corner of the town of Haverhill, bordered to the north by the town of Bath and to the west by the Connecticut River, which forms the state border with Vermont. According to the United States Census Bureau, the CDP has a total area of , of which are land and , or 2.23%, are water. The Ammonoosuc River runs just north of the CDP and reaches its confluence with the Connecticut River at the northernmost point in the community.