Antioch (formerly, East Antioch, Smith's Landing, and Marshs Landing) is a city in Contra Costa County, California. Located in the East Bay region of the San Francisco Bay Area along the San Joaquin-Sacramento River Delta, it is a suburb of San Francisco and Oakland. The city's population was 102,372 at the U.S. 2010 census.

Antioch is one of the oldest towns in California, having been founded in 1850. The year following the discovery of gold, there was a plague that over-took the city and wiped out most of the population.

The town was founded by two brothers, William and Joseph Smith, who named the town Smith’s Landing. In 1851, the town's new minister persuaded the residents to change the name of the town to Antioch, for the Biblical city of Antioch, Turkey.

Around 1859, coal was discovered in several places in the hills south of Antioch and coal mining formed the first substantial business apart from farming and dairying by the inhabitants of this community. This new industry resulted in the founding of the towns of Nortonville, Somersville, Stewartsville, and Black Diamond (now Pittsburg, California), and added greatly to the economic activity of the Antioch area. The Empire Coal Company was formed by John C. Rouse and George Hawxhurst in 1876, which built a railroad that passed from Antioch toward the mines over what is now "F Street" (formerly Kimball Street). However, later on, both the mine and the railroad passed into the hands of the Belshaw brothers. The mines have long ago ceased operation, and the railroad tracks have been dug up, though the building that served as the Antioch terminus of the railroad still stands on the corner of F Street and Fourth Street, and the grading and trestles still remain much as they were in those early days.

Antioch on the Orontes (Greek: Ἀντιόχεια ἡ ἐπὶ Ὀρόντου; or Ἀντιόχεια ἡ ἐπὶ Δάφνῃ, "Antioch on Daphne"; or Ἀντιόχεια ἡ Μεγάλη, "Antioch the Great"; Syriac: ܐܢܛܝܘܟܝܐ Anṭiokia; Hebrew: אנטיוכיה, antiyokhya; Georgian: ანტიოქია; Armenian: Անտիոք Antiok; Latin: Antiochia ad Orontem; Arabic:انطاکیه, Anṭākiya; also Syrian Antioch) was an ancient city on the eastern side of the Orontes River. It is near the modern city of Antakya, Turkey.

Founded near the end of the 4th century BC by Seleucus I Nicator, one of Alexander the Great's generals, Antioch eventually rivaled Alexandria as the chief city of the Near East and was a cradle of Christianity. It was one of the four cities of the Syrian tetrapolis. Its residents are known as Antiochenes. Once a great metropolis of half a million people, it declined to insignificance during the Middle Ages because of repeated earthquakes, the Crusaders' invasions, and a change in trade routes following the Mongol conquests, which then no longer passed through Antioch from the far east.

California (pronounced ⁱ/kælɨˈfɔrnjə/) is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third most extensive (after Alaska and Texas). It is home to the nation's second- and sixth-largest census statistical areas (Los Angeles Metropolitan Area and San Francisco Bay Area), and eight of the nation's fifty most populated cities (Los Angeles, San Diego, San Jose, San Francisco, Fresno, Sacramento, Long Beach and Oakland). The capital city is Sacramento.

California's diverse geography ranges from the Pacific Coast in the west, to the Sierra Nevada mountains in the east – from the Redwood–Douglas-fir forests of the northwest, to the Mojave Desert areas in the southeast. The center of the state is dominated by Central Valley, a major agricultural area. California contains both the highest and lowest points in the contiguous United States (Mount Whitney and Death Valley), and has the third-longest coastline of all states (after Alaska and Florida). Earthquakes are a common occurrence due to the state's location along the Pacific Ring of Fire: about 37,000 are recorded annually.