BNF may refer to:

Science

  • Backus–Naur form, a formal grammar notation in computer science
  • Biological nitrogen fixation
  • British National Formulary, a drug reference manual
  • β-Naphthoflavone, an organic compound

Organisations

  • British Nutrition Foundation, a charity
  • Bibliothèque nationale de France (BnF), the French national library

Political parties

  • Balawaristan National Front, Pakistan
  • Belarusian National Front ()
  • BPF Party, break-away group from 1993 ()
  • Botswana National Front
  • British National Front

Other uses

  • Big Name Fan, a well-known fan