13 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 |
| Lawrence | 2 | 50,054 | 49,342 | 0.24% | 2,484 | 20 | City |
| Beech Grove | 3 | 14,504 | 14,690 | -0.21% | 3,245 | 4 | City |
| Speedway | 4 | 14,425 | 13,953 | 0.55% | 3,014 | 5 | Town |
| Southport | 5 | 2,061 | 2,120 | -0.48% | 3,282 | 1 | City |
| Meridian Hills | 6 | 1,781 | 1,774 | 0.06% | 1,206 | 1 | Town |
| Warren Park | 7 | 1,494 | 1,488 | 0.07% | 3,305 | 0 | Town |
| Homecroft | 8 | 750 | 750 | 0% | 3,125 | 0 | Town |
| Rocky Ripple | 9 | 651 | 651 | 0% | 2,149 | 0 | Town |
| Wynnedale | 10 | 213 | 215 | 0% | 1,340 | 0 | Town |
| Spring Hill | 11 | 95 | 95 | 0% | 888 | 0 | Town |
| Crows Nest | 12 | 69 | 68 | 0% | 161 | 0 | Town |
| North Crows Nest | 13 | 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 13 cities in Marion County, Indiana.