North Dundas is a township in eastern Ontario, Canada, in the United Counties of Stormont, Dundas and Glengarry spread across the South Nation River and the East Castor River.

North Dundas is located within Canada's National Capital Region, approximately midway between Ottawa and Morrisburg. It is primarily rural with a few small villages. The economy is mainly agricultural, most notably producing dairy cattle, corn, and lately soybeans.

The township was incorporated on January 1, 1998 by amalgamating the former townships of Mountain and Winchester with the independent villages of Chesterville and Winchester. The former village of Winchester is the township's primary administrative centre.