Originally settled by United Empire Loyalists in 1785 it was known as Buell's Bay in honour of the founder William Buell. Brockville was renamed in 1812 in honour of General Sir Isaac Brock the national hero of the War of 1812. Brockville was Ontario's first incorporated municipality. The Port of Brockville was connected to the main line of the Grand Trunk Railway by a tunnel constructed beneath the municipality. This was a distinctive feat of engineering acomplished between 1854 and 1860. It is the oldest railway tunnel in Canada, having been inaugurated on December 31, 1860.
Brockville is now home to several industrial manufacturers.