10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Corvallis | 1 | 61,849 | 59,943 | 0.62% | 4,257 | 14.53 | City |
| Philomath | 2 | 5,963 | 5,340 | 2.14% | 2,889 | 2.06 | City |
| Millersburg | 3 | 3,539 | 2,969 | 3.33% | 854 | 4.15 | City |
| Adair Village | 4 | 1,040 | 984 | 1.07% | 2,342 | 0.44 | City |
| Monroe | 5 | 691 | 645 | 1.32% | 1,342 | 0.52 | City |
| Alpine | 6 | 262 | 215 | 2.34% | 305 | 0.86 | CDP |
| Summit | 7 | 221 | 267 | 7.28% | 693 | 0.32 | CDP |
| Kings Valley | 8 | 184 | 194 | 6.98% | 253 | 0.73 | CDP |
| Alsea | 9 | 133 | 220 | -1.48% | 853 | 0.16 | CDP |
| Bellfountain | 10 | 54 | 8 | 8% | 40 | 1.35 | CDP |
Corvallis is the largest city in Benton County, with a population of 61,849.
Bellfountain is the smallest city in Benton County.
There are 10 cities in Benton County, Oregon.