Onondaga County (/ˌɒnənˈdɑːɡə/ ON-ən-DAH-gə) is a county in the U.S. state of New York. As of the 2010 census, the population was 467,026. The county seat is Syracuse. Onondaga County is part of the Syracuse, NY Metropolitan Statistical Area. Joanie Mahoney (R) is the current County Executive.