Polygala smallii is endemic to east-central Florida from southern St. Lucie County through Miami-Dade County. Only 11 documented populations are documented to occur, all of which are found within 10 km (6.2 miles) of the Atlantic coast. Seven of the existing populations currently occur on managed public lands (USFWS 1999). Historically, the northernmost extent of the range was believed to be Broward County, but more recent survey efforts have extended the range into southern St. Lucie county. Polygala smallii may have occurred as far north as Brevard County, but this is uncertain, as the only evidence is a single specimen collected in 1874 labeled "Indian River" (USFWS 1999). Within India River Lagoon Counties, Polygala smallii occurs within 10 km (6.2 miles) of the coast in Palm Beach, Martin and southern St. Lucie Counties (USFWS 1999).