Seffner is a census-designated place (CDP) in Hillsborough County, Florida, United States. The population was 8,362 at the 2020 census, up from 7,579 at the 2010 census. ZIP codes for the Seffner area are 33584 and 33583. Located approximately east of downtown Tampa, Seffner is considered a suburb. Though still characterized by towering live oak trees, strawberry farms and lakes, Seffner has been growing rapidly in recent years, with housing subdivisions being added to the once rural landscape. History Some historians claim that Seffner's streets were originally laid out in 1862, but not recorded as a plat formally until 1885. Seffner's post office opened in 1884 when a new railroad line in the area had been planned. The community was named for its first postmaster, F.P. Seffner. That same year, Seffner's first school and store were opened. Seffner quickly became a prosperous small community with citrus groves, a hotel, one drug store, several dry goods stores and a livery stable. When an epidemic of yellow fever hit Tampa in the fall of 1887 and in 1888, many Tampa refugees fled to Seffner for temporary shelter in the hotel. However, as refugees and mail arrived in Seffner, they were fumigated as protection from the epidemic. Among the refugees was T.C. Taliaferro of the First National Bank of Tampa, who operated a branch banking business from Seffner during the epidemic. The main thoroughfare leading north and south was Lenna Avenue, and leading east and west was Highway Number 23, renamed Buffalo Avenue, because of its erstwhile use as a buffalo trail, and then renamed again in 1989 to its current name, Dr. Martin Luther King, Jr. Boulevard (Hwy 574). Seffner (and neighboring Mango and Dover) served as the three primary towns along the South Florida Railroad right-of-way between Tampa and Plant City. These towns owe their existence and prosperity to the railroad, each becoming an important shipping center. The freeze in the winter of 1894–1895 brought disaster to Seffner. Many citizens left, while others remained to recoup their losses. Seffner survived and regained its affluence. Attractive residential neighborhoods were built to accommodate the influx of desirable residents. By 1925, Seffner was the fourth-largest town in Hillsborough County. Geography Seffner is located northeast of the center of Hillsborough County and is bordered by Thonotosassa to the north, Mango to the west, and Brandon to the south. Interstate 4 is the northern boundary of