| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Indianapolis | 1 | 904,128 | 887,223 | 0.33% | 2,504 | 361 | Township |
| Lawrence | 2 | 50,650 | 49,337 | 0.46% | 2,514 | 20 | City |
| Beech Grove | 3 | 14,667 | 14,686 | -0.03% | 3,282 | 4 | City |
| Speedway | 4 | 14,485 | 13,959 | 0.78% | 3,027 | 5 | Town |
| Southport | 5 | 2,089 | 2,117 | -0.24% | 3,326 | 1 | City |
| Meridian Hills | 6 | 1,805 | 1,775 | 0.28% | 1,222 | 1 | Town |
| Warren Park | 7 | 1,514 | 1,486 | 0.33% | 3,350 | 0 | Town |
| Homecroft | 8 | 762 | 750 | 0.26% | 3,175 | 0 | Town |
| Rocky Ripple | 9 | 659 | 651 | 0.15% | 2,175 | 0 | Town |
| Wynnedale | 10 | 218 | 215 | 0% | 1,371 | 0 | Town |
| Spring Hill | 11 | 97 | 96 | 0% | 907 | 0 | Town |
| Crows Nest | 12 | 68 | 67 | 0% | 159 | 0 | Town |
| North Crows Nest | 13 | 43 | 43 | 0% | 662 | 0 | Town |
Indianapolis is the largest city in Marion County, with a population of 904,128.
North Crows Nest is the smallest city in Marion County, with a population of 43.
There are 13 cities in Marion County, Indiana.