St. Marys is a city in Pleasants County, West Virginia, in the United States. The population was 2,017 at the 2000 census. It is the county seat of Pleasants County. St. Marys was established in 1849 by Alexander Creel, who is said to have had a vision of Mary while passing the town site by boat on the Ohio River.
St. Marys is part of the Parkersburg-Marietta-Vienna, WV-OH Metropolitan Statistical Area. Train tracks run down the middle of 2nd street in St. Marys, and freight trains running through the middle of downtown St. Marys are a common sight. It is one of the few towns in the United States where freight trains actually share streets with automotive traffic.