Onondaga -- U.S. County in New York Population (2000): 458336 Housing Units (2000): 196633 Land area (2000): 780.293445 sq. miles (2020.950659 sq. km) Water area (2000): 25.400019 sq. miles (65.785744 sq. km) Total area (2000): 805.693464 sq. miles (2086.736403 sq. km) Located within: New York (NY), FIPS 36 Location: 43.048433 N, 76.179117 W Headwords: Onondaga Onondaga, NY Onondaga County Onondaga County, NY