Oude-Tonge is a town in the Dutch province of South Holland. It is a part of the municipality of Goeree-Overflakkee, and lies about 16 km south of Hellevoetsluis.In 2015, the town of Oude-Tonge had 5,500 inhabitants. The built-up area of the town was 0.9 km², and contained 1,615 residences. The wider statistical district "Oude-Tonge", which includes the surrounding countryside, has a population of around 5,500. Oude-Tonge was a separate municipality until 1966, when it became part of Oostflakkee. Last one has made part of the new municipality of Goeree-Overflakkee since 2013.