Spackenkill is a hamlet and census-designated place in Dutchess County, New York, United States. The population was 4,123 at the 2010 census. It is part of the Poughkeepsie–Newburgh–Middletown, NY Metropolitan Statistical Area as well as the larger New York–Newark–Bridgeport, NY-NJ-CT-PA Combined Statistical Area. Spackenkill is in the town of Poughkeepsie. Children in the community, if they attend public school, go to the Spackenkill Union Free School District.