The Zaan (Dutch pronunciation: [zaːn]) is a small river in the province of North Holland in the northwestern Netherlands and the name of a district through which it runs. The river was originally a side arm of the IJ bay and travels 13.5 kilometers (8½ miles) through the municipalities of Zaanstad ("Zaan City") and Wormerland north of Amsterdam, from West-Knollendam in the north to Zaandam in the south, where it empties into the IJ.

The municipality of Zaanstad and several towns along the Zaan are named for the river: Koog aan de Zaan, Westzaan, Oostzaan, Zaandijk and the city of Zaandam. The river also runs past the Zaanse Schans, a village with historic windmills and houses.It ranks among the top tourist destinations in the Netherlands.