Marysville
- County:
- Yuba County
- County Seat:
- Yes
- Area (mi²):
- 3.464
- State:
- California
Marysville is a city located in Yuba County, California. Marysville has a 2026 population of 12,714. It is also the county seat of Yuba County. Marysville is currently growing at a rate of 0.09% annually but its population has decreased by -1.07% since the most recent census, which recorded a population of 12,851 in 2020.