Access to Denman Island is by BC Ferries from Buckley Bay, about 20 kilometres north of Courtenay on Vancouver Island. The Buckley Bay terminal is reached by driving north from Nanaimo on Highway 19 (roughly an hour). The ferry crossing takes about 10 minutes and runs frequently throughout the day. No reservations are taken on this route — vehicles queue up.
To reach Hornby Island from Denman, drive across the island to Gravelly Bay (about 10 minutes) and take a second short ferry to Hornby. Having a car makes the islands considerably more accessible, though cycling is feasible. There is no regular bus service on either island.