The Spui is a small tidal river in South Holland in the Netherlands, separating the islands of Voorne-Putten and Hoekse Waard. Historically, it forked off the Oude Maas river at the town of Oud-Beijerland to end in the Haringvliet estuary, but as a (planned) result from the Delta Works, its flow has been reversed.
There are no bridges or tunnels crossing the Spui, but there is a car ferry from Hekelingen (municipality Spijkenisse) to Nieuw-Beijerland (municipality Korendijk), and a pedestrian and bicycle ferry between Oud-Beijerland and Rhoon (in Albrandswaard).
Coordinates: 51°48′44″N 4°19′3″E / 51.81222°N 4.31750°E