Roscoe is a hamlet (and census-designated place) in Sullivan County, New York, United States. The population was 541 at the 2010 census. Roscoe is in the southwest part of the Town of Rockland, adjacent to New York State Route 17. It is named for New York Senator Roscoe Conkling. Roscoe calls itself "Trout Town, USA." The town is a destination for fly-fishing enthusiasts because of its location at the intersection of two rivers popular for trout fishing (the Beaver Kill and the Willowemoc Creek).