Colorado is the state in the United States with 5.2 million populations, has an area of 104,094 sq miles, Denver is the largest city and the Capital of Colorado State has an area of 196.32 square km and a population of 649,495 at the density of 1,514 inhabitants per sq km as per the data of 2013. Spring is the second-largest city in Colorado with a population of 439,886 and the largest area with 504 square km. Northglenn is the city with the highest density at 1,878 inhabitants per square kilometres with a total population of 37,499, the city spread in an area of 19 sq miles.
| Rank | Name | Population | Area (km²) | Density (inhabitants/km²) | County |
|---|---|---|---|---|---|
| 1 | Denver | 649,495 | 396.32 | 1,514 | City and County of Denver[ |
| 2 | Colorado Springs | 439,886 | 504.71 | 826 | El Paso County |
| 3 | Aurora | 345,803 | 398.49 | 814 | Arapahoe County, Adams County, Douglas County |
| 4 | Fort Collins | 152,061 | 141.46 | 1,018 | Larimer County |
| 5 | Lakewood | 147,214 | 111.04 | 1,287 | Jefferson County |
| 6 | Thornton | 127,359 | 90.79 | 1,308 | Adams County, Weld County |
| 7 | Arvada | 111,707 | 99.28 | 1,072 | Adams County, Jefferson County |
| 8 | Westminster | 110,945 | 82.04 | 1,293 | Adams County, Jefferson County |
| 9 | Pueblo | 108,249 | 138.8 | 767 | Pueblo County[ |
| 10 | Centennial | 106,114 | 74.86 | 1,341 | Arapahoe County |
| 11 | Boulder | 103,166 | 64.36 | 1,514 | Boulder County[ |
| 12 | Highlands Ranch | 102,000 | 62.83 | 1539 | Douglas County |
| 13 | Greeley | 96,539 | 122.04 | 761 | Weld County[ |
| 14 | Longmont | 89,919 | 70.59 | 1,222 | Boulder County, Weld County |
| 15 | Loveland | 71,334 | 87.67 | 762 | Larimer County |
| 16 | Grand Junction | 59,778 | 100.85 | 585 | Mesa County[ |
| 17 | Broomfield | 59,471 | 85.42 | 653 | City and County of Broomfield |
| 18 | Castle Rock | 53,063 | 87.71 | 550 | Douglas County[ |
| 19 | Commerce City | 49,799 | 90.42 | 507 | Adams County |
| 20 | Parker | 48,608 | 54.85 | 825 | Douglas County |
| 21 | Littleton | 44,275 | 32.98 | 1,265 | Arapahoe County, Jefferson County, Douglas County |
| 22 | Northglenn | 37,499 | 19.04 | 1,878 | Adams County, Weld County |
| 23 | Brighton | 35,719 | 53.05 | 636 | Adams County, Weld County |
| 24 | Englewood | 31,516 | 16.97 | 1,782 | Arapahoe County |
| 25 | Wheat Ridge | 30,920 | 24.26 | 1,244 | Jefferson County |