Brandon, FL. Brandon is a census-designated place (CDP) in Hillsborough County, Florida, in the United States. As of the 2010 census, the CDP had a total population of 103,483. Its history began on January 20, 1857, when John Brandon (1809–1886) arrived at Fort Brooke (now Tampa) from Mississippi with his first wife Martha (1813–1867) and six sons. At first he moved his family to what is now the Seffner area.