San Bernardino County, officially the County of San Bernardino and sometimes abbreviated as S.B. County, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 U.S. Census, the population was 2,181,654, making it the fifth-most populous county in California and the 14th-most populous in the United States. The county seat is San Bernardino.