West Nyack is a hamlet and census-designated place in the town of Clarkstown, Rockland County, New York, United States. It is located north of Blauvelt, east of Nanuet, southwest of Valley Cottage, southeast of Bardonia, and west of Central Nyack. It is approximately 18 miles north of New York City. The population was 3,439 at the 2010 census.