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, and features the Santa Ynez Airport for general aviation with a paved 2804 x 75 foot runway. The population was 4,418 at the 2010 census, down from 4,584 at the 2000 census.