Reeuwijk (Dutch pronunciation: [ˈreːuʋɛik] ⓘ) is a former municipality in the western Netherlands, in the province of South Holland.

The former municipality of Reeuwijk includes the communities of Driebruggen, Hogebrug, Langeweide, Middelburg, Oud-Reeuwijk, Oukoop, Platteweg, Randenburg, Reeuwijk-Brug, Reeuwijk-Dorp, Sluipwijk, Tempel, Waarder and Westeinde.

Reeuwijk was established as a good location for peat harvesting.

The area prospered in the 18th century when layers of peat were dug up, dried, and used as fuel for industries in Gouda.

Eventually these peat quarries struck a fresh-water spring, forming the Reeuwijk Ponds (Reeuwijkse Plassen).