Cornwall, city in Stormont County, southeastern Ontario, Canada. It is the seat of the united counties of Stormont, Dundas, and Glengarry. Cornwall is a port of entry on the St. Lawrence River. The Seaway International Bridge connects the city to Rooseveltown, New York, in the United States.
Cornwall is a commercial, manufacturing, and distribution center in an agricultural region. Major manufactures include textiles, paper, chemicals, and wood and metal products. High-tech industries grew in importance at the end of the 20th century. The headquarters of the Canadian St. Lawrence Seaway Authority is in Cornwall, as are a branch campus of the University of Ottawa and a branch campus of St. Lawrence College.
