Cornwall is a town in Addison County, Vermont, United States. It was founded November 3, 1761. The population was 1,185 at the 2010 census.
Cornwall is located in south-central Addison County, in the Champlain Valley. It is bordered by the town of Middlebury (the county seat) to the northeast, Salisbury to the southeast, Whiting to the south, Shoreham to the southwest, Bridport to the west, and Weybridge to the north. Otter Creek forms the town border with Salisbury. Vermont Route 30, also known as the "Seth Warner Memorial Highway" and named for notable Vermonter Seth Warner, passes north–south through Cornwall, while Vermont Route 125 passes east–west through the northern part of the town. Vermont Route 74 leads southwest from the center of town, towards the Ticonderoga–Larrabees Point Ferry across Lake Champlain.
According to the United States Census Bureau, the town of Cornwall has a total area of 28.6 square miles (74.1 km2), of which 28.5 square miles (73.7 km2) is land and 0.15 square miles (0.4 km2), or 0.57%, is water.
Cornwall is home to a monument of fallen soldiers from several wars. Most recent inscription is of a soldier who was killed on the Verdun Front on 10 November 1918, a day before the armistice.
As of the census of 2000, there were 1,136 people, 427 households, and 322 families residing in the town. The population density was 39.7 people per square mile (15.3/km2).