Cayuga is an unincorporated community and county seat of Haldimand County, Ontario, Canada located at the intersection of Highway 3 and Munsee Street and along the Grand River. Cayuga is about a 20-minute drive from Lake Erie and 30 minutes south of Hamilton and 115 minutes south of Toronto and consequently it has some cottages and recreational properties in the area. In the past, there was some light industry. It has the local district detachment for the Ontario Provincial Police. It is also uniquely located among larger communities on both the American and Canadian sides of the border boasting television reception from Toronto, Buffalo, New York, Hamilton, Kitchener and Erie, Pennsylvania.

Haldimand County is a rural city-status single-tier municipality on the Niagara Peninsula in Southern Ontario, Canada, on the north shore of Lake Erie, and on the Grand River. Despite its name, it is no longer a county by definition, as all municipal services are handled by a single level of government. Municipal offices are located in Cayuga.