FNI may refer to:
- Fania language, spoken in Chad
- Fellow of the Nautical Institute
- Frankfurt Niederrad station, in Germany
- Friday Nite Improvs
- Fridtjof Nansen Institute, a Norwegian research institute
- Global Ferronickel also known as FNI
- International Naturist Federation (French: ')
- National Car Registration Record (French: '), the 1950-2009 French car registration system.
- Nationalist and Integrationist Front (French: '), a rebel group in the Democratic Republic of the Congo
- Nîmes–Alès–Camargue–Cévennes Airport, in France