Mary's Harbour surrounds the beautiful St. Mary's River. St. Mary's River was the site of a salmon fishery as early as the 1780's. However Mary's Harbour was a permanent settlement until after a fire at Battle Harbour in 1930. The International Grenfell Association decided to relocate its hospital and boarding school, destroyed by the fire, from Battle Harbourr to Mary's Harbour.
Mary's Harbour has always depended on the fishery for its livelihood. Since the cod moratorium the community has thrived on the crab fishery. The Labrador Fishermen's Union Shrimp Company employs over 120 people at the local crab processing facility. It is also the gateway to the National Historic Site of Battle Harbour.