29 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Denver | 1 | 731,868 | 717,620 | 0.39% | 4,781 | 153 | City |
| Aurora | 2 | 407,211 | 386,804 | 1.01% | 2,498 | 163 | City |
| Thornton | 3 | 147,813 | 142,191 | 0.77% | 4,049 | 37 | City |
| Westminster | 4 | 114,964 | 116,653 | -0.29% | 3,636 | 32 | City |
| Commerce City | 5 | 72,109 | 62,788 | 2.65% | 1,974 | 37 | City |
| Brighton | 6 | 44,267 | 40,294 | 1.83% | 2,065 | 21 | City |
| Northglenn | 7 | 38,348 | 38,040 | 0.16% | 5,210 | 7 | City |
| Sherrelwood | 8 | 19,496 | 19,082 | 0.42% | 7,948 | 2 | CDP |
| Welby | 9 | 16,647 | 15,372 | 0.73% | 4,494 | 4 | CDP |
| Federal Heights | 10 | 13,865 | 14,395 | -0.76% | 7,811 | 2 | City |
| Berkley | 11 | 11,179 | 11,299 | -0.02% | 3,108 | 4 | CDP |
| Fairmount | 12 | 11,108 | 9,549 | 2.18% | 1,827 | 6 | CDP |
| Derby | 13 | 9,340 | 9,156 | 1.19% | 5,337 | 2 | CDP |
| Lochbuie | 14 | 8,695 | 8,213 | 1.12% | 2,360 | 4 | Town |
| Shaw Heights | 15 | 5,544 | 5,987 | 0.53% | 8,201 | 1 | CDP |
| Todd Creek | 16 | 5,379 | 4,635 | 2.03% | 544 | 10 | CDP |
| Bennett | 17 | 4,168 | 2,906 | 6.44% | 604 | 7 | Town |
| Strasburg | 18 | 3,324 | 2,987 | 1.78% | 160 | 21 | CDP |
| Watkins | 19 | 1,239 | 746 | 7.18% | 50 | 25 | CDP |
| Comanche Creek | 20 | 570 | 426 | 2.33% | 26 | 22 | CDP |
| Mountain View | 21 | 516 | 538 | -0.96% | 5,548 | 0 | Town |
| Morgan Heights | 22 | 295 | 227 | 0.68% | 1,035 | 0 | CDP |
| North Washington | 23 | 169 | 663 | -11.05% | 33 | 5 | CDP |
| Blue Sky | 24 | 123 | 98 | 7.89% | 3,417 | 0 | CDP |
| Trail Side | 25 | 104 | 138 | 7.22% | 145 | 1 | CDP |
| Brick Center | 26 | 83 | 134 | -2.35% | 14 | 6 | CDP |
| Saddle Ridge | 27 | 66 | 51 | 6.45% | 379 | 0 | CDP |
| Peoria | 28 | 52 | 91 | -11.86% | 4 | 14 | CDP |
| Lakeside | 29 | 14 | 16 | -6.67% | 74 | 0 | Town |
Denver is the largest city in Adams County, with a population of 731,868.
Lakeside is the smallest city in Adams County, with a population of 14.
There are 29 cities in Adams County, Colorado.