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: Fédération naturiste internationale)
 * National Car Registration Record (French: Fichier National des Immatriculations), the 1950-2009 French car registration system.
 * Nationalist and Integrationist Front (French: Front des Nationalistes et Intégrationnistes), a rebel group in the Democratic Republic of the Congo
 * Nîmes–Alès–Camargue–Cévennes Airport, in France