Seaside
- County:
- Monterey County
- County Seat:
- No
- Area (mi²):
- 8.923
- State:
- California
Seaside is a city located in Monterey County, California. Seaside has a 2026 population of 31,524. Seaside is currently declining at a rate of -0.09% annually and its population has decreased by -2.51% since the most recent census, which recorded a population of 32,335 in 2020.