Deer Lake Airport (YDF), 45km northeast of Corner Brook, has flights from Halifax and Toronto with Air Canada and WestJet. The drive from the airport into the city takes about 35 minutes on the Trans-Canada Highway. Car hire is available at the airport and strongly recommended — you will need it to reach Gros Morne and the other sights around the city.
Corner Brook is also the main stop on the drive from the ferry terminal at Port aux Basques, 220km to the southwest. Marine Atlantic runs ferries from North Sydney, Nova Scotia to Port aux Basques year-round, with crossings taking 5 to 7 hours. The Trans-Canada from Port aux Basques to Corner Brook is a decent drive of about 2.5 hours, through increasingly dramatic landscape as you approach the Long Range Mountains. If you are doing the island by car, Corner Brook is the natural first major stop after the ferry.