20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Union | 1 | 25,843 | 25,114 | 0.6% | 232 | 112 | Township |
| Crawfordsville | 2 | 16,744 | 16,326 | 0.5% | 1,676 | 10 | City |
| Clark | 3 | 1,894 | 1,840 | 0.69% | 52 | 36 | Township |
| Brown | 4 | 1,687 | 1,638 | 0.72% | 31 | 54 | Township |
| Wayne | 5 | 1,657 | 1,589 | 0.98% | 46 | 36 | Township |
| Coal Creek | 6 | 1,506 | 1,456 | 0.87% | 28 | 54 | Township |
| Walnut | 7 | 1,369 | 1,328 | 0.74% | 38 | 36 | Township |
| Ladoga | 8 | 1,102 | 1,077 | 0.46% | 2,052 | 1 | Town |
| Waynetown | 9 | 983 | 957 | 0.51% | 2,209 | 0 | Town |
| Ripley | 10 | 921 | 891 | 0.77% | 29 | 32 | Township |
| Scott | 11 | 787 | 763 | 0.77% | 22 | 36 | Township |
| Linden | 12 | 732 | 714 | 0.55% | 1,872 | 0 | Town |
| Darlington | 13 | 724 | 709 | 0.42% | 2,161 | 0 | Town |
| New Market | 14 | 578 | 560 | 0.7% | 2,125 | 0 | Town |
| Waveland | 15 | 437 | 429 | 0.46% | 1,419 | 0 | Town |
| Sugar Creek | 16 | 396 | 387 | 0.51% | 12 | 34 | Township |
| New Richmond | 17 | 316 | 310 | 0.32% | 1,646 | 0 | Town |
| New Ross | 18 | 314 | 308 | 0.32% | 1,050 | 0 | Town |
| Wingate | 19 | 249 | 239 | 0.81% | 1,284 | 0 | Town |
| Alamo | 20 | 66 | 65 | 0% | 1,065 | 0 | Town |
Union is the largest city in Montgomery County, with a population of 25,843.
Alamo is the smallest city in Montgomery County, with a population of 66.
There are 20 cities in Montgomery County, Indiana.