18 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Indianapolis | 1 | 892,551 | 887,213 | 0.12% | 2,472 | 361 | Township |
| Center | 2 | 154,460 | 153,424 | 0.54% | 3,679 | 42 | Township |
| Wayne | 3 | 150,209 | 148,362 | 0.58% | 3,084 | 49 | Township |
| Lawrence | 4 | 123,853 | 122,259 | 0.58% | 2,638 | 47 | Township |
| Perry | 5 | 122,881 | 121,695 | 0.59% | 2,676 | 46 | Township |
| Pike | 6 | 84,172 | 83,013 | 0.7% | 2,018 | 42 | Township |
| Lawrence | 7 | 49,935 | 49,342 | 0.24% | 2,478 | 20 | City |
| Beech Grove | 8 | 14,535 | 14,690 | -0.21% | 3,252 | 4 | City |
| Speedway | 9 | 14,346 | 13,953 | 0.55% | 2,997 | 5 | Town |
| Southport | 10 | 2,071 | 2,120 | -0.48% | 3,298 | 1 | City |
| Meridian Hills | 11 | 1,780 | 1,774 | 0.06% | 1,205 | 1 | Town |
| Warren Park | 12 | 1,493 | 1,488 | 0.07% | 3,303 | 0 | Town |
| Homecroft | 13 | 750 | 750 | 0% | 3,125 | 0 | Town |
| Rocky Ripple | 14 | 651 | 651 | 0% | 2,149 | 0 | Town |
| Wynnedale | 15 | 213 | 215 | -0.47% | 1,340 | 0 | Town |
| Spring Hill | 16 | 95 | 95 | 0% | 888 | 0 | Town |
| Crows Nest | 17 | 69 | 68 | 0% | 161 | 0 | Town |
| North Crows Nest | 18 | 44 | 44 | 0% | 677 | 0 | Town |
Indianapolis is the largest city in Marion County, with a population of 892,551.
North Crows Nest is the smallest city in Marion County, with a population of 44.
There are 18 cities in Marion County, Indiana.