Douglas County, Colorado Zip Codes
| Parker | 75,383 |
| Littleton | 43,691 |
| Parker | 36,113 |
| Castle Rock | 35,084 |
| Castle Rock | 33,259 |
| Littleton | 29,974 |
| Castle Rock | 27,852 |
| Littleton | 25,551 |
| Lone Tree | 22,567 |
| Littleton | 13,048 |
| Larkspur | 5,940 |
| Franktown | 4,884 |
| Sedalia | 4,061 |
| Louviers | 250 |
- Population is the most recent figure from the U.S. Census Bureau's 2022 American Community Survey (ACS) 5-Year Estimates.