Monsey is a hamlet (and census-designated place), in the Town of Ramapo, Rockland County, New York, United States located north of the state of New Jersey; east of Suffern; south of Airmont and west of Nanuet. The 2010 census listed the population at 18,412.
The hamlet has a large and influential community of Orthodox Jews, consisting predominantly of Chasidim, Hareidim and other Orthodox groups, as well as the Vizhnitz-Monsey hasidim who reside mostly in the Village of Kaser.
Rockland County was inhabited by the Munsee band of Lenape Native Americans, or Delaware Indian, of the Algonquian languages. Monsey Glen, an Indian encampment, is located west of the intersection of NY 59 and NY 306. Numerous artifacts have been found there and some rock shelters are still visible. The Monsey railroad station, which received its name from Munsee, a Lenape chief, was built when the New York & Erie Railroad passed through the glen in 1841. In the 1950s, Monsey was a one stoplight town with a single yeshiva. By 1997, Monsey had 112 synagogues and 45 yeshivas.
Located near Monsey is the Houser-Conklin House, listed on the National Register of Historic Places in 2010.