Pasco County is a county located on the west central coast of the U.S. state of Florida. According to the 2020 census, the population was 561,691, making it the eleventh-most populous county in the state. Its county seat is Dade City, and its largest city is Zephyrhills. The county is named after Samuel Pasco. Pasco County is included in the Tampa Bay Area and is primarily a bedroom community for Tampa and St. Petersburg.