Grosse-Île is one of two municipalities forming the urban agglomeration of Îles-de-la-Madeleine. It is part of the Gaspésie–Îles-de-la-Madeleine region, and its population was 465
in 2016.
As part of a municipal reorganization across Quebec, the seven communities of the Magdalen Islands amalgamated to form the municipality of Les Îles-de-la-Madeleine
in 2002. However, after a 2004 referendum, Grosse-Île decided to split from the municipality, effective January 1, 2006.