Morrisburg is an unincorporated community in the Municipality of South Dundas, located in Eastern Ontario, Canada. The population was 2,398 at the 2021 census.

South Dundas is a municipality in eastern Ontario, Canada, in the United Counties of Stormont, Dundas and Glengarry along the north shore of the St. Lawrence River. It is located approximately 100 kilometres south of Ottawa and is midway between Kingston and Montreal, Quebec.