The Township of Thorold, which included the hamlets of Allanburg, Beaverdams, Port Robinson, St. John's and Thorold South, was incorporated in 1798, while the Town of Thorold was incorporated as a village in 1850 and as a Town in 1875. In 1970 the new Town of Thorold was created by combining the former Township of Thorold and the former Town of Thorold. On the first day of July, 1975, the new Town of Thorold became the Corporation of The City of Thorold.
In 1824, the first Welland Canal was built. The fourth and present Canal was completed in 1932. The Canal attracts thousands who view, with wonder, the giant gates that trap the water to maneuver huge ships up or down the Niagara Escarpment between Lake Erie and Lake Ontario. Although there are other Flight Locks in the world, Thorold's twin locks are unique in that they lift ships higher or lower, over a shorter distance. This heritage rich city is situated on top of the Niagara Escarpment, 350 feet above sea level.
Thorold's appreciation for its heritage is reflected in the many homes, churches and buildings of its ancestors that have been designated historical sites.