3 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Oak Harbor | 1 | 24,046 | 24,628 | -0.48% | 2,492 | 10 | City |
| Coupeville | 2 | 1,931 | 1,949 | -0.21% | 1,520 | 1 | Town |
| Langley | 3 | 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 3 cities in Island County, Washington.