West Stewartstown is a census-designated place in the town of Stewartstown in Coos County, New Hampshire, United States. It had a population of 386 at the 2010 census.It is located along U.S. Route 3 and the Connecticut River in the northwestern corner of Stewartstown, directly across the river from Canaan, Vermont, and one mile south of the Canada–US border. Route 3 leads south 8 miles to Colebrook and northeast 10 miles to Pittsburg. The nearest international border crossings are Canaan–Hereford Road, 1.9 miles northwest of West Stewartstown via Vermont Routes 114 and 141, and Beecher Falls–East Hereford, 2.2 miles to the northeast via Vermont Route 253.According to the United States Census Bureau, the West Stewartstown CDP has a total area of 0.64 square miles, of which 0.61 square miles are land and 0.03 square miles, or 4.28%, are water.As of the census of 2010, there were 386 people, 119 households, and 76 families residing in the CDP.