Walnut
- County:
- Los Angeles County
- County Seat:
- No
- Area (mi²):
- 8.989
- State:
- California
Walnut is a city located in Los Angeles County, California. Walnut has a 2026 population of 27,250. Walnut is currently declining at a rate of -0.12% annually and its population has decreased by -3.88% since the most recent census, which recorded a population of 28,350 in 2020.