As with all vernacular regions, South Florida has no official boundaries or status and is defined differently by different sources. A 2007 study of Florida's regions by Ary Lamme and Raymond K. Oldakowski found that Floridians surveyed identified "South Florida" as comprising the southernmost sections of peninsular Florida. That area includes the Miami metropolitan area (generally defined as Miami-Dade, Broward, and Palm Beach counties), the Florida Keys, and the interior region known as the Glades. Additionally, Southwest Florida, representing the state's southern Gulf Coast, has emerged as a directional vernacular region. Some respondents from as far northwest as the southern Tampa Bay area identified their region as being in South Florida rather than Southwest or Central Florida.
Enterprise Florida, the state's economic development agency, identifies "Southeast Florida" as one of eight economic regions used by the agency and other state and outside entities, including the Florida Department of Transportation. Some entities alternately designate this region "South Florida". Its definition includes much of the same territory as Lamme and Oldakowski's report (except the Gulf Coast and much of the interior Glades region) as well as additional area. It includes Monroe County (the Keys) and the three metropolitan counties of Miami-Dade, Broward, and Palm Beach, as well as the three "Treasure Coast" counties of Indian River, St. Lucie, and Martin to the north. Source From Wikipedia