17 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portland | 1 | 631,394 | 652,522 | -0.69% | 4,730 | 133 | City |
| Portland | 2 | 631,394 | 653,166 | -0.69% | 4,730 | 133 | City |
| Gresham | 3 | 110,761 | 114,265 | -0.67% | 4,709 | 24 | City |
| Gresham | 4 | 110,761 | 114,490 | -0.67% | 4,709 | 24 | City |
| Bethany | 5 | 33,567 | 28,047 | 2.63% | 6,168 | 5 | CDP |
| Cedar Mill | 6 | 20,302 | 18,661 | 1.93% | 6,099 | 3 | CDP |
| Troutdale | 7 | 15,610 | 16,295 | -0.88% | 2,625 | 6 | City |
| Troutdale | 8 | 15,610 | 16,304 | -0.88% | 2,625 | 6 | City |
| Fairview | 9 | 10,895 | 10,421 | 0.92% | 3,527 | 3 | City |
| Fairview | 10 | 10,895 | 10,397 | 0.92% | 3,527 | 3 | City |
| Rockcreek | 11 | 10,075 | 9,698 | 0.51% | 5,125 | 2 | CDP |
| West Haven-Sylvan | 12 | 8,470 | 8,505 | 0.38% | 3,776 | 2 | CDP |
| Wood Village | 13 | 4,805 | 4,389 | 1.76% | 5,101 | 1 | City |
| Wood Village | 14 | 4,805 | 4,388 | 1.76% | 5,101 | 1 | City |
| Maywood Park | 15 | 804 | 830 | -0.74% | 4,674 | 0 | City |
| Maywood Park | 16 | 804 | 833 | -0.74% | 4,674 | 0 | City |
| Fairview | 17 | 619 | 594 | 7.09% | 1,373 | 0 | CDP |
Portland is the largest city in Multnomah County, with a population of 631,394.
Fairview is the smallest city in Multnomah County, with a population of 619.
There are 17 cities in Multnomah County, Oregon.