44 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marion | 1 | 28,007 | 28,251 | -0.17% | 1,784 | 15.70 | City |
| Center township | 2 | 21,654 | 21,609 | 0.32% | 867 | 24.96 | Township |
| Van Buren township | 3 | 12,765 | 12,813 | -0.17% | 366 | 34.85 | Township |
| Mill township | 4 | 10,444 | 10,443 | 0.32% | 451 | 23.18 | Township |
| Marion township | 5 | 8,811 | 8,820 | -0.17% | 133 | 66.34 | Township |
| Pleasant township | 6 | 6,983 | 6,982 | 0.29% | 200 | 34.83 | Township |
| Marion township | 7 | 6,671 | 6,667 | 0.09% | 127 | 52.62 | Township |
| Gas City | 8 | 6,059 | 6,138 | -0.26% | 1,205 | 5.03 | City |
| Jefferson township | 9 | 5,703 | 5,680 | 0.28% | 137 | 41.77 | Township |
| Van Buren township | 10 | 4,276 | 4,221 | 0.16% | 114 | 37.65 | Township |
| Van Buren township | 11 | 4,261 | 4,317 | -0.47% | 121 | 35.23 | Township |
| Marion township | 12 | 4,035 | 3,844 | 1% | 116 | 34.75 | Township |
| Fairmount township | 13 | 3,979 | 3,963 | 0.38% | 131 | 30.43 | Township |
| Upland | 14 | 3,805 | 3,812 | -0.03% | 1,213 | 3.14 | Town |
| Van Buren township | 15 | 3,206 | 3,199 | 0.12% | 100 | 32.18 | Township |
| Van Buren township | 16 | 2,919 | 2,909 | 0.41% | 78 | 37.48 | Township |
| Van Buren township | 17 | 2,741 | 2,797 | -0.69% | 91 | 30.22 | Township |
| Fairmount | 18 | 2,648 | 2,675 | -0.19% | 1,670 | 1.59 | Town |
| Marion township | 19 | 2,008 | 1,909 | 1.06% | 59 | 34.11 | Township |
| Van Buren township | 20 | 1,960 | 1,920 | 0.46% | 22 | 87.20 | Township |
| Marion township | 21 | 1,900 | 1,927 | -0.47% | 77 | 24.82 | Township |
| Van Buren township | 22 | 1,815 | 1,779 | 0.55% | 73 | 24.98 | Township |
| Van Buren township | 23 | 1,793 | 1,786 | 0.34% | 51 | 35.48 | Township |
| Marion township | 24 | 1,676 | 1,697 | -0.24% | 30 | 55.48 | Township |
| Sims township | 25 | 1,660 | 1,677 | 0% | 69 | 24.08 | Township |
| Marion township | 26 | 1,548 | 1,499 | 0.45% | 40 | 38.51 | Township |
| Jonesboro | 27 | 1,494 | 1,513 | -0.27% | 1,673 | 0.89 | City |
| Marion township | 28 | 1,416 | 1,456 | -0.42% | 45 | 31.71 | Township |
| Van Buren township | 29 | 1,395 | 1,453 | -1.27% | 50 | 27.90 | Township |
| Marion township | 30 | 1,258 | 1,240 | 0.56% | 27 | 45.94 | Township |
| Marion township | 31 | 1,126 | 1,109 | 0.63% | 34 | 32.98 | Township |
| Sweetser | 32 | 1,058 | 1,072 | -0.28% | 1,050 | 1.01 | Town |
| Marion township | 33 | 916 | 909 | 0% | 26 | 35.88 | Township |
| Swayzee | 34 | 895 | 912 | -0.33% | 1,908 | 0.47 | Town |
| Van Buren township | 35 | 825 | 839 | -0.36% | 23 | 36.28 | Township |
| Van Buren | 36 | 781 | 786 | -0.13% | 1,340 | 0.58 | Town |
| Marion township | 37 | 677 | 686 | -0.15% | 19 | 35.41 | Township |
| Matthews | 38 | 496 | 493 | 0.2% | 1,409 | 0.35 | Town |
| Green township | 39 | 450 | 455 | 0% | 16 | 27.74 | Township |
| Herbst | 40 | 443 | 144 | 5.23% | 3,257 | 0.14 | CDP |
| Fowlerton | 41 | 273 | 270 | 0.37% | 1,393 | 0.20 | Town |
| Point Isabel | 42 | 93 | 91 | 8.14% | 163 | 0.57 | CDP |
| Landess | 43 | 71 | 89 | -8.97% | 50 | 1.41 | CDP |
| Sims | 44 | 71 | 93 | -7.79% | 243 | 0.29 | CDP |
Marion is the largest city in Grant County, with a population of 28,007.
Sims is the smallest city in Grant County.
There are 44 cities in Grant County, Indiana.