Goeree-Overflakkee (Dutch pronunciation: [ɣuˌreː ˈoːvərflɑˌkeː]) is the southernmost delta island of the province of South Holland, Netherlands.

It is separated from Voorne-Putten and Hoeksche Waard by the Haringvliet, from the mainland of North Brabant by the Volkerak, and from Schouwen-Duiveland by Lake Grevelingen.

The island was detached from the mainland when the Haringvliet formed as a result of two major flooding events.

In the St. Elizabeth floods of 1421, this inlet connected to the Merwede and became an important estuary of the Rhine and Meuse rivers.

With a long beach nearby, Ouddorp is a tourist attraction and has a number of camping sites.

Next to Stellendam lies the Haringvlietdam which shelters the Haringvliet from the North Sea, this dam is part of the Delta Project.

The 1953 flood did not have such an effect on these places, as they are mainly lie on higher ground than the rest of the island.

The former municipality of Oostflakkee consists of: Den Bommel (with Zuidzijde), Oude-Tonge, Ooltgensplaat, Achthuizen, and Langstraat.

This town hosts the start and finish of De Omloop – an annual 100+ km walk around the island within a 24-hour period.

The island of Gorée in Senegal, notorious in the 18th century as a center for the slave trade, got its name from the Dutch Goeree at the time when it was ruled by the Netherlands (from 1588 to 1664).