Chestnut Ridge is a village in the town of Ramapo, Rockland County, New York, United States, located north of the state of New Jersey, east of Airmont, south of Spring Valley, and west of Nanuet. The population was 10,505 at the 2020 census. Chestnut Ridge was incorporated in 1986. Prior to 1986, Chestnut Ridge was an unincorporated area within the town of Ramapo often referred to as "South Spring Valley", as many postal addresses carried the Spring Valley designation.