Stormont, Dundas and Glengarry United Counties is a county and census division in Ontario, Canada. The county seat is Cornwall.
The county borders with Quebec to the east and New York State to the south.

Municipalities

City of Cornwall
Township of North Dundas
Township of North Glengarry
Township of North Stormont
Township of South Dundas
Township of South Glengarry
Township of South Stormont