The Haringvliet is a large inlet of the North Sea, in the province of South Holland in the Netherlands. It is an important estuary of the Rhine-Meuse delta.

Near Numansdorp, the Hollands Diep splits into the Haringvliet and the Volkerak estuaries. It is closed off near Goedereede from the North Sea by the Haringvliet sluices, which provide a road connection between the island of Voorne to the north and the island of Goeree-Overflakkee to the south. The sluices were built as part of the Delta Works sea barrier protection works, and allow for a brackish ecological environment.

The Haringvliet estuary contains the island of Tiengemeten, which is separated from the river island of Hoeksche Waard by the Vuile Gat strait.