| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Oak Harbor | 1 | 23,947 | 24,626 | -0.56% | 2,481 | 10 | City |
| Coupeville | 2 | 1,915 | 1,945 | -0.26% | 1,508 | 1 | Town |
| Langley | 3 | 1,125 | 1,151 | -0.35% | 1,116 | 1 | City |
Oak Harbor is the largest city in Island County, with a population of 23,947.
Langley is the smallest city in Island County, with a population of 1,125.
There are 3 cities in Island County, Washington.