FNI
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
 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