Top 5 Cities in Illinois by Population (2024 Estimates)

1. Chicago – 2,746,388 (metro 9.5M)
2. Aurora – 197,899
3. Naperville – 149,540
4. Joliet – 149,260
5. Rockford – 147,403

Notes: Aurora overtook Rockford for #2 in the 2010s. Naperville and Joliet are essentially tied. Springfield (capital) is #6 (~114,000). Peoria #7 (~110,000). Chicago dominates—21% of state population in the city proper, 75% in the metro.