XF4 may refer to:
Aircraft Douglas F4D Skyray (prototype designation XF4D-1), jet fighter-interceptor Grumman F4F Wildcat (experimental designations XF4F-1 to XF4F-3), monoplane fighter McDonnell Douglas F-4 Phantom II (experimental designation XF4H-1), jet fighter-bomber Vought F4U Corsair (experimental designation XF4U-1), monoplane fighter
Other uses The X Factor (British series 4), British TV series Radio callsign for the Revillagigedo islands in Mexico - see Call signs in Mexico