thumb|225px|right|Satellite image of the northwest part of the [[Rhine-Meuse delta showing river Spui (p).]]
thumb|225px|right|Ferry across the Spui at Nieuw-Beijerland.
The Spui is a small tidal river in South Holland in the Netherlands, connecting the river Oude Maas and the Haringvliet estuary, separating the islands of Voorne-Putten and Hoeksche Waard. Historically, it forked off the Oude Maas at the town of Oud-Beijerland to end in the Haringvliet, but as a (planned) result from the Delta Works, its flow has been reversed. The Spui emerged as a result of a levee breach during the ,