Yolo County is located in the northern part of the U.S. state of California, bordered by the counties of Sacramento, Solano, Napa, Lake, Colusa, and Sutter. Woodland is the county seat.
As of the 2000 census, Yolo County had a population of 168,660, and notwithstanding the presence of the University of California, Davis in its midst and the state capital in the neighboring county of Sacramento, Yolo County remains a relatively rural agricultural area, home to the multi-billion dollar California tomato industry, which dominates 90% of the tomato market in the United States.
Yolo County was one of the original cheese farm counties of California, created on on 18 February 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.