Santa Ynez is a census-designated place (CDP) in Santa Barbara County, California, United States. The town of Santa Ynez is one of the communities that make up the Santa Ynez Valley, serving general aviation needs for the valley with the paved 2804 x 75 foot Santa Ynez Airport. The population was 4,584 at the 2000 census. It is named after Saint Agnes, Ynez being the former Spanish language spelling.