10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Oak Harbor | 1 | 24,046 | 24,622 | -0.48% | 2,492 | 10 | City |
| Oak Harbor | 2 | 24,046 | 24,628 | -0.48% | 2,492 | 10 | City |
| Camano | 3 | 22,053 | 17,073 | 7.15% | 555 | 40 | CDP |
| Whidbey Island Station | 4 | 2,717 | 2,375 | 2.96% | 414 | 7 | CDP |
| Coupeville | 5 | 1,931 | 1,944 | -0.21% | 1,520 | 1 | Town |
| Coupeville | 6 | 1,931 | 1,949 | -0.21% | 1,520 | 1 | Town |
| Freeland | 7 | 1,856 | 1,883 | -0.7% | 478 | 4 | CDP |
| Clinton | 8 | 1,224 | 1,123 | 1.66% | 1,209 | 1 | CDP |
| Langley | 9 | 1,136 | 1,148 | -0.26% | 1,127 | 1 | City |
| Langley | 10 | 1,136 | 1,149 | -0.26% | 1,127 | 1 | City |
Oak Harbor is the largest city in Island County, with a population of 24,046.
Langley is the smallest city in Island County, with a population of 1,136.
There are 10 cities in Island County, Washington.