Deer Island is located in the Bay of Fundy at the entrance to Passamaquoddy Bay. Deer Island is located in West Isles Parish and is part of the Fundy Islands in Charlotte County.
At 45 km, the island is the largest in the West Isles Parish which had a 2001 population of 851.
The major communities on the island are Fairhaven, Leonardville, Lords Cove and Cummings Cove.
The economy is primarily driven by the fishing and aquaculture industries although tourism is growing in importance.
The island is famous for playing host to Old Sow, the largest tidal whirlpool in the western hemisphere. Deer Island Point is also popular with scuba divers for its marine life.
Deer Island is entirely rural with only one major route which is Route 772.
The provincially operated L’Etete to Deer Island Ferry connects Deer Island with L’Etete on the Canadian mainland throughout the year.
During the summer, privately operated ferries operate the Cummings Cove to Welshpool Ferry which goes to Campobello Island, and the Cummings Cove to Eastport Ferry which goes to the U.S. state of Maine.