| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Woodbury | 1 | 82,765 | 75,473 | 1.48% | 2,372 | 35 | City |
| Cottage Grove | 2 | 44,514 | 38,985 | 2.09% | 1,323 | 34 | City |
| Oakdale | 3 | 31,103 | 28,263 | 1.68% | 2,838 | 11 | City |
| Forest Lake | 4 | 20,938 | 20,703 | -0.07% | 686 | 31 | City |
| Stillwater | 5 | 19,336 | 19,402 | -0.09% | 2,403 | 8 | City |
| Hugo | 6 | 17,392 | 15,807 | 1.31% | 520 | 33 | City |
| Lake Elmo | 7 | 15,071 | 11,347 | 4.83% | 682 | 22 | City |
| Mahtomedi | 8 | 8,197 | 8,141 | 0.1% | 2,364 | 3 | City |
| Newport | 9 | 5,889 | 3,941 | 6.59% | 1,628 | 4 | City |
| St. Paul Park | 10 | 5,355 | 5,544 | -0.76% | 1,786 | 3 | City |
| Oak Park Heights | 11 | 4,568 | 4,843 | -1.23% | 1,561 | 3 | City |
| Scandia | 12 | 3,968 | 3,987 | -0.28% | 114 | 35 | City |
| Bayport | 13 | 3,641 | 4,032 | -2.15% | 2,101 | 2 | City |
| Afton | 14 | 2,957 | 2,956 | -0.1% | 118 | 25 | City |
| Lakeland | 15 | 1,645 | 1,711 | -0.84% | 793 | 2 | City |
| Lake St. Croix Beach | 16 | 995 | 1,042 | -1% | 1,770 | 1 | City |
| Landfall | 17 | 845 | 845 | -0.24% | 12,803 | 0 | City |
| Marine on St. Croix | 18 | 659 | 664 | -0.3% | 169 | 4 | City |
| Willernie | 19 | 510 | 524 | -0.58% | 4,080 | 0 | City |
| Pine Springs | 20 | 379 | 388 | -0.52% | 492 | 1 | City |
| St. Marys Point | 21 | 340 | 353 | -0.87% | 881 | 0 | City |
| Lakeland Shores | 22 | 324 | 341 | -0.92% | 1,025 | 0 | City |
Woodbury is the largest city in Washington County, with a population of 82,765.
Lakeland Shores is the smallest city in Washington County, with a population of 324.
There are 22 cities in Washington County, Minnesota.