Oroville is the county seat of Butte County, California, United States. The population of the city was 15,506 at the 2010 census, up from 13,004 in the 2000 census. Following the 2018 Camp Fire that destroyed much of the town of Paradise, the population of Oroville increased as many people who lost their homes relocated to nearby Oroville. In 2020, the 2020 census recorded the population of Oroville at 20,042.