18 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Indianapolis | 1 | 893,619 | 887,213 | 0.12% | 2,475 | 361 | Township |
| Center | 2 | 155,294 | 153,424 | 0.54% | 3,699 | 42 | Township |
| Wayne | 3 | 151,069 | 148,362 | 0.57% | 3,102 | 49 | Township |
| Lawrence | 4 | 124,573 | 122,259 | 0.58% | 2,654 | 47 | Township |
| Perry | 5 | 123,606 | 121,695 | 0.59% | 2,691 | 46 | Township |
| Pike | 6 | 84,753 | 83,013 | 0.69% | 2,032 | 42 | Township |
| Lawrence | 7 | 50,054 | 49,342 | 0.24% | 2,484 | 20 | City |
| Beech Grove | 8 | 14,504 | 14,690 | -0.21% | 3,245 | 4 | City |
| Speedway | 9 | 14,425 | 13,953 | 0.55% | 3,014 | 5 | Town |
| Southport | 10 | 2,061 | 2,120 | -0.48% | 3,282 | 1 | City |
| Meridian Hills | 11 | 1,781 | 1,774 | 0.06% | 1,206 | 1 | Town |
| Warren Park | 12 | 1,494 | 1,488 | 0.07% | 3,305 | 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% | 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 893,619.
North Crows Nest is the smallest city in Marion County, with a population of 44.
There are 18 cities in Marion County, Indiana.