Yolo County is located in the northern part of the U.S. state of California, bordered by the other counties of Sacramento, Solano, Napa, Lake, Colusa, and Sutter. The city of Woodland is its county seat, though Davis is its largest city.
As of the 2010 census, Yolo County had a population of 200,849. Excluding the conurbation of the University of California, Davis and the surrounding City of Davis, and the area neighboring the City of Sacramento, Yolo County remains a relatively rural agricultural region. This is evidenced by the multi-billion dollar California tomato industry, centering on Yolo County, dominating 90% of the canning and processed tomato market in the United States.
The eastern part of Yolo County is in the Sacramento metropolitan area.
Yolo County was one of the original counties of California, created in 1850 at the time of statehood.
In the original act of 1850 the name was spelled "Yola." Yolo is a Native American name variously believed to be a corruption of a tribal name Yo-loy meaning "a place abounding in rushes" or of the name of the chief, Yodo, or of the village of Yodoi.