
Lewis County
- State:
- Washington
- County Seat:
- Chehalis
Lewis County's estimated 2025 population is 87,748 with a growth rate of 0.92% in the past year according to the most recent United States census data. Lewis County is the 15th largest county in Washington. The 2010 population was 75,503 and has seen a growth of 16.22% since that time.