
Whatcom County
- State:
- Washington
- County Seat:
- Bellingham
Whatcom County's estimated 2025 population is 234,561 with a growth rate of 0.57% in the past year according to the most recent United States census data. Whatcom County is the 9th largest county in Washington. The 2010 population was 201,549 and has seen a growth of 16.38% since that time.