Buttonwillow is a census-designated place in the San Joaquin Valley, in Kern County, California, United States. Buttonwillow is located 26 miles west of Bakersfield, at an elevation of 269 feet). The population was 1,508 at the 2010 census, up from 1,266 at the 2000 census. The center of population of California is located in Buttonwillow.