Governador Island, island, the largest island (12 square miles [31 square km]) in Guanabara Bay, southeastern Brazil. Linked to the mainland and Rio de Janeiro by bridge, it is the site of a naval air station and shipyards. The main campus of the Federal University of Rio de Janeiro is located on a smaller island between Governador Island and the mainland. The international airport of Galeão, opened there in 1977, is about 10 miles (16 km) from Rio de Janeiro’s centre.