17 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Center township | 1 | 151,059 | 153,408 | -0.21% | 3,598 | 41.98 | Township |
| Wayne township | 2 | 147,997 | 148,353 | 0.2% | 3,039 | 48.70 | Township |
| Lawrence township | 3 | 121,307 | 122,260 | -0.09% | 2,584 | 46.95 | Township |
| Perry township | 4 | 120,193 | 121,694 | -0.15% | 2,617 | 45.93 | Township |
| Pike township | 5 | 82,246 | 83,008 | -0.08% | 1,972 | 41.72 | Township |
| Lawrence | 6 | 49,164 | 49,341 | -0.07% | 2,440 | 20.15 | City |
| Speedway | 7 | 14,293 | 13,952 | 0.48% | 2,986 | 4.79 | Town |
| Beech Grove | 8 | 14,246 | 14,685 | -0.61% | 3,188 | 4.47 | City |
| Southport | 9 | 2,032 | 2,121 | -0.88% | 3,236 | 0.63 | City |
| Meridian Hills | 10 | 1,740 | 1,774 | -0.4% | 1,178 | 1.48 | Town |
| Warren Park | 11 | 1,461 | 1,488 | -0.34% | 3,232 | 0.45 | Town |
| Homecroft | 12 | 735 | 750 | -0.41% | 3,063 | 0.24 | Town |
| Rocky Ripple | 13 | 637 | 651 | -0.47% | 2,102 | 0.30 | Town |
| Wynnedale | 14 | 211 | 216 | -0.47% | 1,327 | 0.16 | Town |
| Spring Hill | 15 | 91 | 93 | 0% | 850 | 0.11 | Town |
| Crows Nest | 16 | 63 | 67 | -1.56% | 147 | 0.43 | Town |
| North Crows Nest | 17 | 41 | 43 | 0% | 631 | 0.07 | Town |
Center township is the largest city in Marion County, with a population of 151,059.
North Crows Nest is the smallest city in Marion County.
There are 17 cities in Marion County, Indiana.