Pinellas County is a county located on the central Western portion of Florida. its largest city is St. Petersburg. This county is contained entirely within the telephone area code 727, except for some sections of Oldsmar, which has the area code 813. Pinellas County, together with Hillsborough County, Hernando County, and Pasco County, composes the Tampa-St.Petersburg-Clearwater Metropolitan area, which is often referred to as the Tampa Bay Area.