A fen is a type of wetland.
Fen, Fenn, Fens, Fenns, may also refer to:
People Fen (name), a Chinese given name and surname Fen Cresswell (1915–1966), New Zealand cricketer Fen McDonald (1891–1915), Australian rules footballer Kees Fens (1920–2008), Dutch writer Vitaly Fen (born ), Uzbekistani diplomat
Places Back Bay Fens, a park in Boston, Massachusetts The Fens, a low-lying geographical region of eastern England Fenns, Indiana, an unincorporated community Fen Complex, Norway, an area of unusual igneous rocks Fen Prefecture, a region of Imperial China Fen River, in China Fenn College, predecessor of Cleveland State University Fenn Tower, building on the campus of Cleveland State University Fenn's Moss, part of a British nature reserve
Chinese units of measurement Fen (currency), , a unit of the renminbi, the currency of China Fen (land), , a Chinese unit of land area Fen (length), , a Chinese unit of length
Other uses Fen (band), a British metal band Fen (play), a play by the British playwright Caryl Churchill Far East Network, a network of American military radio and television stations Federation of European Neuroscience Societies (FENS), a scholarly federation Fen TV, a Bulgarian television channel Fenny Stratford railway station, in England Fernando de Noronha Airport, in Brazil Festival of New Songs, a Slovenian music festival Final Exit Network (FEN), an American right-to-die advocacy group Flap endonuclease Forsyth–Edwards Notation (FEN) for chess positions Fédération des Étudiants Nationalistes (FEN), a defunct French far-right students' association Fen or three-legged turtle from Chinese mythology FAA Enterprise Network Services (FENS) of the Federal Aviation Administration