6 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portland | 1 | 631,394 | 653,166 | -0.69% | 4,730 | 133 | City |
| Gresham | 2 | 110,761 | 114,490 | -0.67% | 4,709 | 24 | City |
| Troutdale | 3 | 15,610 | 16,304 | -0.88% | 2,625 | 6 | City |
| Fairview | 4 | 10,895 | 10,397 | 0.92% | 3,527 | 3 | City |
| Wood Village | 5 | 4,805 | 4,388 | 1.76% | 5,101 | 1 | City |
| Maywood Park | 6 | 804 | 833 | -0.74% | 4,674 | 0 | City |
Portland is the largest city in Multnomah County, with a population of 631,394.
Maywood Park is the smallest city in Multnomah County, with a population of 804.
There are 6 cities in Multnomah County, Oregon.