Tonopah is an unincorporated community and census-designated place in western Maricopa County, Arizona, United States, 52 miles west of downtown Phoenix off Interstate 10. The community is near the Palo Verde Nuclear Generating Station, the largest power producer in the country, nuclear or otherwise. As of the 2020 census, the population of Tonopah was 23, down from 60 at the 2010 census. It is located on the Tonopah Desert.