Bonaventure Island (officially in French: île Bonaventure) is an island in the Gulf of St. Lawrence located 3.5 kilometres (2.2 mi) off the southern coast of Quebec's Gaspé Peninsula, 5 kilometres (3.1 mi) southeast of the village of Percé in Canada. Roughly circular in shape, it has an area measuring 4.16 square kilometres (1.61 sq mi).
Bonaventure Island (Île Bonaventure), with Percé, was among the early seasonal fishing ports of New France, and was associated with the lineage of Nicolas Denys. Settlers from southern Ireland came in the early 1790s. Peter Du Val, a native of Jersey, set up a fishery company on lot number one before 1819, population rose to an apex, but the company endured until 1845. The island became a migratory bird sanctuary in 1919 due to the 1916 Migratory Bird Convention between Canada and the United States. The Province of Quebec acquired ownership of the entire island by act of expropriation in 1971, evicting the whole population. At this time approximately 35 families were forced to move elsewhere, all residents were evicted. Later the Province of Quebec grouped it together with Percé Rock into the Parc national de l'île-Bonaventure-et-du-Rocher-Percé (Bonaventure Island and Percé Rock National Park) in 1985. One of the largest and most accessible bird sanctuaries in the world, with more than 280,000 birds, Bonaventure Island is a major tourist destination with boat and island tours from May to October.
The aircraft carrier HMCS Bonaventure was named after the island.
293 different species of birds have been recorded as visiting, migrating to, or living on Bonaventure island.
The most common bird found on the island is the northern gannet. The island is home to one of the largest colonies of gannets in the world, with 47,800 pairs in 2011. This is down from 2009, when there were over 121,000 birds. Other populous colonies include the black-legged kittiwake and the common murre. terns, black guillemots, auks, herring gulls, great black-backed gulls, razorbills, Leach's storm-petrels, great cormorants, double-crested cormorants, Atlantic puffins, boreal chickadees and blackpoll warblers can also be observed on Bonaventure.