
Onondaga County
- State:
- New York
Onondaga County's estimated 2025 population is 464,163 with a growth rate of -0.4% in the past year according to the most recent United States census data. Onondaga County is the 11th largest county in New York. The 2010 population was 467,549 and has seen a growth of -0.72% since that time.