BNF may refer to:

Science[edit]

• 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[edit]

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

Political parties[edit]

• Balawaristan National Front, Pakistan
• Belarusian National Front (Belarusian: Belaruskі Narodny Front)
  • BPF Party, break-away group from 1993 (Belarusian: Partyja BNF)
• Botswana National Front

Other uses[edit]

• Big Name Fan, a well-known fan