The Canso Causeway connects Cape Breton Island to the mainland of the province of Nova Scotia in eastern Canada. Completed in 1955, the mile long causeway crosses the Strait of Canso between Cape Porcupine, Nova Scotia on the mainland and Port Hastings, Nova Scotia on Cape Breton Island. The Canso Canal is located at the eastern end of the causeway.

Before the construction of the causeway, Cape Breton Island was connected to the mainland by ferries for carrying railway cars and later, motor vehicles. Ferries used included: Mulgrave (1893-1901), Scotia I (1903-1955), and Scotia II (1915-1955).

Canso comes from the Mi'kmaq word kamsok, which means "opposite the lofty cliffs."