FNUF may refer to:

• United Nations Forum on Forests (UNFF), in its French-language abbreviation
• Front national pour l’unité française, a predecessor of the French right-wing party Front National

• William Nicol (MP)
• William Nicolson Cuthbert
• William Nielsen
• William Nigel Stock
• William Nightingale
• William Ni'i Haomae
• William Nimmo Smith
• William Nimmo Smith, Lord Nimmo Smith
• William Nisbet
• William Nisbet (disambiguation)
• William Njobvu
• William Njoku
• William Njovu
• William N. Leonard
• William N. McKelvy Sr.
• William N. Morris
• William Noah Hedges
• William Noble
• William Noble, 1st Baron Kirkley
• William Noble (disambiguation)
• William Nobles (disambiguation)
• William Noel
• William Noel-Hill, 3rd Baron Berwick, PC, FSA
• William Noel Hodgson
• William Nolan (disambiguation)