Saint-Vrain (French pronunciation: [sɛ̃ vʁɛ̃] ⓘ) is a commune in the Essonne department in Île-de-France in northern France.

Since 2001, Thaxted (Essex, England) has been twinned with Saint-Vrain.

A twinning association aims to promote friendship and cultural understanding and to foster the relationship between the two towns and their people.

A castle with a historic zoological park (with reconstructions of prehistoric scenes) is located here, but has been closed to the public since 1998.

The town also has a Louis XV-era obelisk and a thirteenth-century church.