10 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marion | 1 | 28,197 | 28,253 | -0.03% | 1,796 | 16 | City |
| Gas City | 2 | 6,068 | 6,137 | -0.18% | 1,207 | 5 | City |
| Upland | 3 | 3,821 | 3,815 | 0.03% | 1,218 | 3 | Town |
| Fairmount | 4 | 2,661 | 2,676 | -0.08% | 1,678 | 2 | Town |
| Jonesboro | 5 | 1,502 | 1,513 | -0.13% | 1,682 | 1 | City |
| Sweetser | 6 | 1,072 | 1,071 | 0% | 1,063 | 1 | Town |
| Swayzee | 7 | 901 | 913 | -0.22% | 1,921 | 0 | Town |
| Van Buren | 8 | 786 | 785 | 0% | 1,348 | 1 | Town |
| Matthews | 9 | 486 | 482 | 0.21% | 1,381 | 0 | Town |
| Fowlerton | 10 | 274 | 270 | 0.37% | 1,398 | 0 | Town |
Marion is the largest city in Grant County, with a population of 28,197.
Fowlerton is the smallest city in Grant County, with a population of 274.
There are 10 cities in Grant County, Indiana.