By plane
Sydney is served by the nearby Sydney Airport which is served year round by Air Canada with prop service to Halifax and seasonal CRJ service to Montreal.
During the summer the airport is served by Air Saint-Pierre with flights from Saint-Pierre and Miquelon and Sunwing Airlines with flights from Toronto. Prince Edward Air also provides charter flights.
By car
Driving to Sydney can be done by crossing the Canso Causeway which links the island to the Nova Scotia mainland at Canso. From there you have two options: the slightly longer but straighter Highways 105 and 125 or the shorter but twistier Route 4.
By ship
North Sydney is the site of the Marine Atlantic terminal which serves as the main connection to Newfoundland. From the ferry terminal it is about a 20 minute drive on Highway 125 to Sydney.