F18

F18, F-18 or F.XVIII may refer to:
 * McDonnell Douglas F/A-18 Hornet, an American all-weather carrier-capable multirole fighter jet
 * Boeing F/A-18E/F Super Hornet, more advanced derivative of the F/A-18 Hornet
 * F-18 (Michigan county highway)
 * Fokker F.XVIII, a 1932 Dutch airliner
 * HMS Zulu (F18), a 1937 British Royal Navy Tribal-class destroyer
 * Formula 18, a class of catamaran
 * Fluorine-18 (F-18 or F18F), an unstable isotope of fluorine
 * Slip F-18, anchorage for the fictional houseboat The Busted Flush