(Oct. 26, 1813), in the War of 1812, engagement in which the British compelled U.S. forces to abandon a projected attack on Montreal and thus exerted a decisive influence on U.S. strategy during the 1813 campaign.

In the autumn of 1813, a U.S. invading force of about 4,000 troops under General Wade Hampton marched toward Montreal through the Châteauguay River valley. A U.S. advance party of 1,500 under Colonel Robert Purdy and some 460 British troops under Colonel Charles de Salaberry met at Châteauguay on October 26. The British had taken up a good defensive position in the woods along the riverbank and, despite their inferior numbers, managed to stop Purdy's advance. After this setback, Hampton withdrew back across the border. At least 90 percent of the British troops at Châteauguay were French Canadians.