Rock Hill is a hamlet in Sullivan County, New York, United States. At the 2020 census the population was 2,369.

Sullivan County is a county in the U.S. state of New York. As of the 2020 census, the population was 78,624. The county seat is Monticello. The county's name honors Major General John Sullivan, who was labeled at the time as a hero in the American Revolutionary War in part due to his successful campaign against the Iroquois. The county is part of the Hudson Valley region of the state.