Pearl River is a hamlet and census-designated place in the town of Orangetown, Rockland County, New York, United States. It is east of Chestnut Ridge, south of Nanuet, west of Blauvelt, New York, and north of Montvale and Old Tappan, New Jersey. The population was 15,876 at the 2010 census. Pearl River is 20 miles north of midtown Manhattan and just north of the New Jersey border. It is the first of three New York stops on New Jersey Transit's Pascack Valley Line.