Newark is a city in Alameda County, California, United States. It was incorporated as a city in September 1955. Newark is an enclave, completely surrounded by the city of Fremont. Its population was 42,573 at the 2010 census.
The southern end of the San Francisco Bay lies near the western edge of the city. State Route 84 runs through the city, and continues as the Dumbarton Bridge to cross the San Francisco Bay to reach Menlo Park. Interstate 880 serves as the eastern boundary with Fremont.
According to the United States Census Bureau, the city has a total area of 13.9 square miles (36.0 km²), of which, 13.9 square miles (35.9 km²) of it is land and 0.02 square miles (0.1 km²) of it (0.17%) is water.