Mt. Eden was an unincorporated agricultural district in Eden Township, Alameda County, California, United States]. It was annexed by the City of Hayward. It lies at an elevation of 43 feet.
Mt. Eden was founded in 1850 by a group of farmers from Mount Eden, Kentucky, drawn to California by the Gold Rush. The party disbanded upon reaching the San Francisco Bay, but a few settled at a road crossing where they nailed a sign "Mt. Eden" to two trees, and the name stuck. A post office opened in 1860 and was in continuous operation until 1953.