19 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Lockhart | 1 | 17,866 | 14,382 | 4.08% | 1,144 | 16 | City |
| Lockhart | 2 | 17,866 | 14,364 | 4.08% | 1,144 | 16 | City |
| Luling | 3 | 5,791 | 5,607 | 0.68% | 1,051 | 6 | City |
| Luling | 4 | 5,791 | 5,593 | 0.68% | 1,051 | 6 | City |
| Redwood | 5 | 3,194 | 3,349 | -2.32% | 496 | 6 | CDP |
| Uhland | 6 | 1,955 | 1,584 | 3.71% | 702 | 3 | City |
| Uhland | 7 | 1,955 | 1,602 | 3.71% | 702 | 3 | City |
| Martindale | 8 | 1,270 | 1,252 | 0.32% | 616 | 2 | City |
| Martindale | 9 | 1,270 | 1,250 | 0.32% | 616 | 2 | City |
| Mustang Ridge | 10 | 1,015 | 942 | 1.3% | 272 | 4 | City |
| Mustang Ridge | 11 | 1,015 | 950 | 1.3% | 272 | 4 | City |
| Niederwald | 12 | 731 | 670 | 1.53% | 199 | 4 | City |
| Niederwald | 13 | 731 | 674 | 1.53% | 199 | 4 | City |
| Mountain City | 14 | 687 | 625 | 1.63% | 1,306 | 1 | City |
| Mountain City | 15 | 687 | 632 | 1.63% | 1,306 | 1 | City |
| Creedmoor | 16 | 414 | 461 | -2.13% | 54 | 8 | City |
| Creedmoor | 17 | 414 | 459 | -2.13% | 54 | 8 | City |
| Hays | 18 | 272 | 226 | 3.03% | 1,220 | 0 | City |
| Hays | 19 | 272 | 229 | 3.03% | 1,220 | 0 | City |
Lockhart is the largest city in Caldwell County, with a population of 17,866.
Hays is the smallest city in Caldwell County, with a population of 272.
There are 19 cities in Caldwell County, Texas.