Goeree-Overflakkee (Dutch pronunciation: [ɣuˌreː ˈoːvərflɑˌkeː]) is a delta island and an administrative municipality in the province of South Holland, Netherlands, with a population of 50,589. It is the largest island by land area in the Netherlands after the man-made Flevopolder.
Goeree-Overflakkee is separated from the islands of Voorne-Putten and Hoeksche Waard by the Haringvliet, from the mainland of North Brabant by the Volkerak, and from Schouwen-Duiveland by Lake Grevelingen.