Wynantskill is a hamlet and census-designated place (CDP) in Rensselaer County, New York, United States. The population was 3,018 at the 2000 census. Wynantskill is located at the north town line and the northeast corner of the town of North Greenbush. The community is a suburb of Troy. NY Route 66 (Pawling Ave. in Troy, Main Ave. in Wynantskill) is the main route throughout the community. Wynantskill has a major grocery store, several banks, restaurants, convenience stores, a post office, and a bowling alley, with almost all houses located on side streets off Main Ave. Other major roads are Whiteview Road, a primarily residential road that leads to Route 4; and West Sand Lake Road.
Wynantskill is located at 42°41′32″N 73°38′40″W / 42.69222°N 73.64444°W / 42.69222; -73.64444 (42.692139, -73.644580).
According to the United States Census Bureau, the CDP has a total area of 2.4 square miles (6.3 km²), all land.