The area gets its name from the Dennis family (led by John Dennis (1758–1832)), Loyalist shipbuilders who owned the property, as well as a boatyard on the Humber, at the turn of the 19th century. It remained largely rural, with orchards, gravel and clay pits and a few market gardens. Kodak Canada moved its factory to a site at Eglinton Avenue and Weston Road, along the rail line running next to Weston Road, in 1913. This factory complex, known as "Kodak Heights", was a major employer for Mount Dennis' residents until it was shut down in 2005.