Ossining is a village in Westchester County, New York, United States. The population at the 2020 United States census was 27,551, an increase from 25,060 at the 2010 census. As a village, it is located in the town of Ossining. Some iconic places: Rockefeller State Park Preserve, Croton Point Park, The Great Jack O’Lantern Blaze: Hudson Valley