Mossyrock
- County:
- Lewis County
- County Seat:
- No
- Area (mi²):
- 0.688
- State:
- Washington
Mossyrock is a city located in Lewis County, Washington. Mossyrock has a 2026 population of 803. Mossyrock is currently growing at a rate of 0.75% annually and its population has increased by 3.88% since the most recent census, which recorded a population of 773 in 2020.