The town of Rohnert Park was named after the Rohnert family who owned the Rohnert Seed Farm. In 1929, a successful businessman, Waldo Emerson Rohnert, purchased a large ranch here and minimized flooding in the fields with a crude drainage system but died shortly after. His son, Fred Rohnert, a graduate of Stanford Law School took over the ranch and developed a seed growing business, the Rohnert Seed Farm, which turned into a major horticultural success for the county.
In the year 1956, only four adult residents lived within the district boundaries, but in 1957 with the 101 Freeway newly completed at the Cotati bypass, Rohnert Park began to be built and laid out as a planned city. In 1962, Rohnert Park was incorporated, the first town in Sonoma County to incorporate since 1905.