St. Catharines began its existence as a community in the late 18th century. The city is home to the Welland Canal, built in the 1820s, where visitors can still watch huge ships maneuver through the locks. The St. Catharines Museum tell the story of the Canals, the city’s establishment, growth, and importance in Canadian history with many highlights stemming from St. Catharines such as the ‘zipper’.

In 1871, construction began on the third Welland Canal, which attracted additional population to the town. As a consequence of continual growth, the town limits were again extended. St. Catharines attained city status in 1876 with its larger population and area. By 1881, there were more acres in urban use in St. Catharines than there were rural acres in use.

The city is named after Catharine Hamilton, wife of Robert Hamilton, an influential merchant of Queenston and a landowner with mills on Twelve Mile Creek; the incipient community, then known as The Twelve or Shipman's Corners, was renamed in her honour after her death in 1796.