Marysville is a city in and the county seat of Yuba County, California, United States, located at the confluence of two rivers which drain the watersheds containing the most productive gold mining region in Northern California. As the depot for the Northern mines it became an important early center of commerce, growing into one of the largest cities in California's first decade of existence, before the gold gave out. It is one of just two cities in California named after a woman who is not considered a Catholic saint, being named after a survivor of the Donner Party which lost half its party to starvation in the Sierra Nevada in the winter of 1846–47.
As of the 2010 United States Census, the population was 12,072, reflecting a decrease of 196 from the 12,268 counted in the 2000 Census. It is included in the Yuba City Metropolitan Statistical Area, often referred to as the Yuba–Sutter area after the two counties, Yuba and Sutter. The metropolitan statistical area is part of the Greater Sacramento area.
Marysville is located on the ancestral land of the Maidu, who occupied the area for 10,000 years prior to the arrival of Jedediah Smith and trappers from the Hudson Bay Company in 1828, who were the first non-natives to explore the area. Spanish and Mexican explorers never reached that far north on the Feather River. In 1842, John Sutter leased part of his Rancho New Helvetia land to Theodore Cordua, a native of Mecklenburg in Germany, who raised livestock, and in 1843 built a home and trading post he called New Mecklenburg. The trading post and home was situated at what would later become the southern end of 'D' Street, Marysville's main street.