Seffner is a census-designated place (CDP) in Hillsborough County, Florida, United States.

Located approximately 13 miles (21 km) 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.

Some historians claim that Seffner's streets were originally laid out in 1862, but not recorded as a plat formally until 1885.

[5] 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.

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.

[7] The Seffner Civic Center is a historical land site with a basketball court, picnic tables, a playground, and a large open field.

[9] The Life Fellowship Bird Sanctuary located in Seffner, affiliated with a local church.

Birds and reptiles are kept there, and the facility is noted for its success in breeding rock iguanas in captivity.