Ramapo is a town in Rockland County, New York, United States. It was originally formed as New Hampstead, in 1791, and became Ramapo in 1828. It shares its name with the Ramapo River. As of the 2020 census, Ramapo had a total population of 148,919, making it the most populous town in New York outside of Long Island. If all towns in New York were cities, Ramapo would be the 12th-largest city in the state of New York.