St. Marys is a town in southwestern Ontario, Canada. It is located at the junction of Thames River and Trout Creek, southwest of Stratford and surrounded by the Township of Perth South. It is in the Perth census division but is independent of Perth County. The town is also known by its nickname, "The Stone Town", due to the abundance of limestone in the surrounding area, giving rise to a large number of limestone buildings and homes throughout the town. St. Marys Cement, a large cement producer founded in the town, capitalized on this close feedstock, and grew to be a major producer of cement in the province of Ontario.

St. Marys is home to the Canadian Baseball Hall of Fame. It is the burial place of Arthur Meighen, Canada's 9th Prime Minister. Timothy Eaton, who went on to become one of Canada's greatest retailers, opened his first businesses in Canada in St. Marys and nearby Kirkton, Ontario.

In 1839 the Canada Company sent a surveyor to Blanshard Township in the Huron Tract to choose a site for a town on the Thames River which would later be named St. Marys.

The first settlers arrived in St. Marys in the early 1840s, attracted by the area's natural resources. At the new town site, the Thames River cascaded over a series of limestone ledges, providing the power to run the first pioneer mills and giving the community an early nickname: Little Falls.

In the riverbed and along the banks, limestone was close to the surface and could be quarried for building materials. Many 19th century limestone structures survive: churches, commercial blocks, and private homes. They have given St. Marys its current nickname: Stonetown.

The arrival of the Grand Trunk Railway in the late 1850s spurred growth and soon St. Marys became a centre for milling, grain-trading and the manufacture of agriculture-related products. The railway connected the town to the rest of the world and framed the local landscape with its two large trestle bridges on limestone pillars across the waterways.

St. Marys contains many 19th century buildings built with locally quarried limestone. Notable buildings include the Opera House built in 1880, the spired municipal Town Hall built in 1891, and the Public Library built in 1904.

The Canadian Baseball Hall of Fame moved to St. Marys from Toronto in 1994 and opened in 1998. It is dedicated to preserving Canada's baseball heritage. Since opening, 75 members (46 players, 23 builders, 2 honorary, 4 honorary teams) have been inducted. It includes professional ballplayers, amateurs, builders and honorary members who have helped popularize the sport in Canada. The facility also includes a baseball field designed by landscape architect Art Lierman of London, Ontario.

The Grand Trunk Trail is a walkway transformed from a two kilometre section of the former Grand Trunk Railway line. The trail features a walk over the restored Sarnia bridge, providing panoramic views over the town.

en.wikipedia.org/wiki/St._Marys,_Ontario