Riverside is a city in and the county seat of Riverside County, California, United States, in the Inland Empire metropolitan area. It is named for its location beside the Santa Ana River.[10] It is the most populous city in the Inland Empire and in Riverside County, and is about 50 miles (80 km) southeast of downtown Los Angeles. It is also part of the Greater Los Angeles area. Riverside is the 59th-most-populous city in the United States and the 12th-most-populous city in California. As of the 2020 census, it had a population of 314,998.[7] Along with San Bernardino, Riverside is a principal city in the nation's 13th-largest Metropolitan Statistical Area (MSA); the Riverside-San Bernardino-Ontario MSA (pop. 4,599,839) ranks in population just below San Francisco (4,749,008) and above Detroit (4,392,041).

Riverside was founded in the early 1870s. It is the birthplace of the California citrus industry and home of the Mission Inn, the nation's largest Mission Revival Style building.[11] It is also home to the Riverside National Cemetery and the Eastern Division of the Federal District Court for the Central District of California.

The University of California, Riverside, is in the northeastern part of the city. The university hosts the Riverside Sports Complex. Other attractions in Riverside include the Fox Performing Arts Center, Museum of Riverside, which houses exhibits and artifacts of local history, the California Museum of Photography, the California Citrus State Historic Park, Castle Park, and the Parent Washington Navel Orange Tree, the last of California's two original navel orange trees.[12