Fresno is a major city in the San Joaquin Valley of California, United States. It is the county seat of Fresno County and the largest city in the greater Central Valley region. It covers about 115 square miles and had a population of 542,107 as of the 2020 Census, making it the fifth-most populous city, in California, the most populous inland city in California, and the 34th-most populous city in the nation.