Cathlamet
- County:
- Wahkiakum County
- County Seat:
- Yes
- Area (mi²):
- 0.506
- State:
- Washington
Cathlamet is a town located in Wahkiakum County, Washington. Cathlamet has a 2026 population of 608. It is also the county seat of Wahkiakum County. Cathlamet is currently growing at a rate of 0.83% annually and its population has increased by 7.99% since the most recent census, which recorded a population of 563 in 2020.