Cromstrijen (Dutch: [krɔmˈstrɛiə(n)] ⓘ; Cromstrien in local dialect) was a municipality on the Hoeksche Waard Island in the western Netherlands, in the province of South Holland.

On 1 January 2019 it was merged with the municipalities of Binnenmaas, Korendijk, Oud-Beijerland, and Strijen to form the municipality of Hoeksche Waard.

The municipality of Cromstrijen consists of the communities Klaaswaal and Numansdorp (townhall).

Dutch topographic map of the municipality of Cromstrijen, June 2015

This South Holland location article is a stub.