Williamstown is a city in Wood County, West Virginia, United States, along the Ohio River. It is part of the Parkersburg-Marietta-Vienna, WV-OH Metropolitan Statistical Area. The population was 2,996 at the 2000 census. The Fenton Art Glass Company is located in the city.
Williamstown is located at 39°23′58″N 81°27′2″W / 39.39944°N 81.45056°W / 39.39944; -81.45056 (39.399574, -81.450558).
According to the United States Census Bureau, the city has a total area of 1.8 square miles (4.6 km²), of which, 1.3 square miles (3.5 km²) of it is land and 0.4 square miles (1.1 km²) of it (23.86%) is water.