44 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marion | 1 | 28,206 | 28,253 | -0.04% | 1,796 | 16 | City |
| Center | 2 | 21,666 | 21,617 | 0.25% | 868 | 25 | Township |
| Van Buren | 3 | 12,773 | 12,812 | -0.34% | 367 | 35 | Township |
| Mill | 4 | 10,407 | 10,444 | 0.07% | 449 | 23 | Township |
| Marion | 5 | 8,945 | 8,822 | 0.54% | 135 | 66 | Township |
| Pleasant | 6 | 6,997 | 6,987 | 0.29% | 201 | 35 | Township |
| Marion | 7 | 6,548 | 6,669 | -0.74% | 124 | 53 | Township |
| Gas City | 8 | 6,079 | 6,137 | -0.2% | 1,209 | 5 | City |
| Jefferson | 9 | 5,691 | 5,670 | 0.25% | 136 | 42 | Township |
| Van Buren | 10 | 4,335 | 4,317 | 0.35% | 123 | 35 | Township |
| Van Buren | 11 | 4,299 | 4,227 | 0.33% | 114 | 38 | Township |
| Marion | 12 | 4,073 | 3,845 | 1.32% | 117 | 35 | Township |
| Fairmount | 13 | 3,981 | 3,964 | 0.33% | 131 | 30 | Township |
| Upland | 14 | 3,820 | 3,815 | 0.03% | 1,217 | 3 | Town |
| Van Buren | 15 | 3,181 | 3,202 | -0.19% | 99 | 32 | Township |
| Van Buren | 16 | 2,947 | 2,909 | 1.1% | 79 | 37 | Township |
| Van Buren | 17 | 2,778 | 2,799 | -0.18% | 92 | 30 | Township |
| Fairmount | 18 | 2,663 | 2,676 | -0.11% | 1,679 | 2 | Town |
| Marion | 19 | 1,997 | 1,909 | 0.81% | 59 | 34 | Township |
| Marion | 20 | 1,946 | 1,928 | 0.67% | 78 | 25 | Township |
| Van Buren | 21 | 1,943 | 1,918 | -0.15% | 22 | 87 | Township |
| Van Buren | 22 | 1,836 | 1,777 | 1.05% | 73 | 25 | Township |
| Van Buren | 23 | 1,784 | 1,785 | 0.17% | 50 | 35 | Township |
| Marion | 24 | 1,706 | 1,696 | 0.47% | 31 | 55 | Township |
| Sims | 25 | 1,673 | 1,678 | 0.24% | 69 | 24 | Township |
| Marion | 26 | 1,553 | 1,498 | 0.45% | 40 | 39 | Township |
| Jonesboro | 27 | 1,504 | 1,513 | -0.13% | 1,684 | 1 | City |
| Van Buren | 28 | 1,448 | 1,453 | 0.49% | 52 | 28 | Township |
| Marion | 29 | 1,406 | 1,457 | -1.06% | 44 | 32 | Township |
| Marion | 30 | 1,274 | 1,240 | 1.11% | 28 | 46 | Township |
| Marion | 31 | 1,104 | 1,109 | -0.09% | 33 | 33 | Township |
| Sweetser | 32 | 1,072 | 1,071 | 0% | 1,063 | 1 | Town |
| Marion | 33 | 932 | 910 | 0.22% | 26 | 36 | Township |
| Swayzee | 34 | 903 | 913 | -0.22% | 1,925 | 0 | Town |
| Van Buren | 35 | 834 | 839 | 0% | 23 | 36 | Township |
| Van Buren | 36 | 786 | 785 | 0% | 1,348 | 1 | Town |
| Marion | 37 | 685 | 686 | 0.15% | 19 | 35 | Township |
| Matthews | 38 | 485 | 482 | 0% | 1,378 | 0 | Town |
| Green | 39 | 451 | 453 | 0.22% | 16 | 28 | Township |
| Herbst | 40 | 443 | 144 | 5.23% | 3,257 | 0 | CDP |
| Fowlerton | 41 | 273 | 270 | 0% | 1,393 | 0 | Town |
| Point Isabel | 42 | 93 | 91 | 8.14% | 163 | 1 | CDP |
| Landess | 43 | 71 | 89 | -8.97% | 50 | 1 | CDP |
| Sims | 44 | 71 | 93 | -7.79% | 243 | 0 | CDP |
Marion is the largest city in Grant County, with a population of 28,206.
Sims is the smallest city in Grant County, with a population of 71.
There are 44 cities in Grant County, Indiana.