Waldon is a former census-designated place (CDP) in Contra Costa County, California, United States. The population was 5,133 at the 2000 census. The Pittsburg/Bay Point – SFO Line line of the Bay Area Rapid Transit system serves the surrounding area using the Pleasant Hill/Contra Costa Centre Station with an adjacent to Interstate 680. The area has been undergoing a series of transit-oriented development projects under the auspices of the Contra Costa Centre Transit Village public/private partnership.
Waldon's territory has been assumed by Contra Costa Centre CDP for the 2010 census.