Esopus is a town in Ulster County, New York, United States. The population was 9,548 at the 2020 census. The town was named after the local indigenous tribe and means "small river" in English. They were one of the Lenape (Delaware) bands, belonging to a people who ranged from western Connecticut through lower New York, western Long Island, and parts of New Jersey and Pennsylvania along the Delaware River. The town is on the west bank of the Hudson River south of the city of Kingston. Its center is in Port Ewen. US Route 9W passes along the eastern side of the town.

Ulster County is a county in the U.S. state of New York. It is situated along the Hudson River. As of the 2020 census, the population was 181,851. The county seat is Kingston. The county is named after the Irish province of Ulster. The county is part of the Hudson Valley region of the state.