The Spui is a small tidal river in South Holland in the Netherlands. It forks off the Oude Maas river at the town of Oud-Beijerland and ends in the Haringvliet estuary.

There are no bridges or tunnels crossing the Spui, but there is a car ferry from Voorne-Putten island on the north near Spijkenisse to Hoekse Waard island on the south near Nieuw-Beijerland.