20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Union | 1 | 25,588 | 25,118 | 0.11% | 229 | 112 | Township |
| Crawfordsville | 2 | 16,656 | 16,345 | 0.37% | 1,667 | 10 | City |
| Clark | 3 | 1,877 | 1,843 | 0.16% | 52 | 36 | Township |
| Brown | 4 | 1,677 | 1,643 | 0.24% | 31 | 54 | Township |
| Wayne | 5 | 1,632 | 1,587 | 0.43% | 45 | 36 | Township |
| Coal Creek | 6 | 1,484 | 1,453 | 0.27% | 28 | 54 | Township |
| Walnut | 7 | 1,358 | 1,326 | 0.3% | 37 | 36 | Township |
| Ladoga | 8 | 1,100 | 1,079 | 0.36% | 2,048 | 1 | Town |
| Waynetown | 9 | 978 | 956 | 0.41% | 2,198 | 0 | Town |
| Ripley | 10 | 916 | 894 | 0.44% | 29 | 32 | Township |
| Scott | 11 | 781 | 765 | 0.26% | 22 | 36 | Township |
| Linden | 12 | 729 | 713 | 0.41% | 1,864 | 0 | Town |
| Darlington | 13 | 723 | 707 | 0.42% | 2,158 | 0 | Town |
| New Market | 14 | 560 | 548 | 0.36% | 2,059 | 0 | Town |
| Waveland | 15 | 441 | 431 | 0.46% | 1,432 | 0 | Town |
| Sugar Creek | 16 | 395 | 388 | 0% | 12 | 34 | Township |
| New Richmond | 17 | 316 | 311 | 0.32% | 1,646 | 0 | Town |
| New Ross | 18 | 313 | 308 | 0.32% | 1,047 | 0 | Town |
| Wingate | 19 | 250 | 243 | 0.4% | 1,289 | 0 | Town |
| Alamo | 20 | 67 | 65 | 0% | 1,081 | 0 | Town |
Union is the largest city in Montgomery County, with a population of 25,588.
Alamo is the smallest city in Montgomery County, with a population of 67.
There are 20 cities in Montgomery County, Indiana.