Yuba City (yōˈbə) [key], town (1990 pop. 27,437), seat of Sutter co., N central Calif., on the Feather River; founded 1849 during the gold rush; inc. 1908. It is a growing processing center for fruits, walnuts, rice, grains, and vegetables. Medical instruments and farm machinery are among its manufactures. Beale Air Force Base is in the vicinity.