F4

F4, F.IV, F04, F 4, F.4 or F-4 may refer to:

Aircraft

Boeing P-12, which around 1930 was also known as the F4B
Caproni Vizzola F.4, an Italian prototype fighter of 1941
F-4 Lightning, a reconnaissance variant of the P-38 WW II fighter
F-4 Phantom II, a supersonic fighter-bomber made by McDonnell Douglas
F4D Skyray, a United States Navy fighter aircraft used in the 1960s
F4F Wildcat, a United States Navy fighter aircraft in World War II
F4U Corsair, a United States Navy fighter aircraft in World War II and the Korean War
Flanders F.4, a 1910s British experimental military two-seat monoplane aircraft
Fokker F.IV, a 1921 Dutch airliner
Hunter F 4, a Hawker Hunter variant

F₄, one of the five exceptional simple Lie groups
F4 lattice, one of three regular space-filling tessellation in Euclidean 4-space
F₄ or 65,537 - the fourth Fermat number and largest known Fermat prime

F4 layout, a front-engine, four-wheel drive auto layout
MV Agusta F4 series, a series of motorcycles
USS F-4 (SS-23), a United States submarine that sunk near Honolulu harbor in 1915
Sydney Ferries' Darling Harbour ferry services, known as the F4

F4 (paper), a paper size of 210 mm by 330 mm
F 4 Frösön, a former Swedish Air Force wing
F-number f/4, a standard expressing the diameter of the aperture on a camera
F-4 Object, or Rákosi bunker, a formerly secret nuclear shelter under the downtown of Budapest, Hungary
Form F-4, an SEC form used to register securities in the United States
Nikon F4, a camera
F4, Albarka Air's IATA airline designator
F4, a tornado intensity rating on the Fujita scale