Fib
Fib or FIB may refer to:

Places
Kingdom of Fib, now Fife, Scotland

Arts, entertainment, and media
Fib (poetry), a form of poetry
Festival Internacional de Benicàssim, a Spanish music festival
Folket i Bild, a Swedish news magazine

Enterprises
First International Bank (Liberia)
First Investment Bank, a Bulgarian bank

Medicine
Fascia iliaca block
Fibrillarin
Fibrillation
Fibrinogen
Fibula

Science and technology
FiB index, or Fisheries in Balance index
Flying inflatable boat
Focused ion beam
Forwarding information base
Fluoride-ion Battery

Sport
Federation of International Bandy
Fédération Internationale de Boules, the highest international authority of bocce sport

Other uses
Fib (lie), a form of bending the truth  that is usually forgiven because it is not intended to deceive
Fill in the blanks, an exercise in which certain parts of a sentence are omitted for the participant to fill in
Barcelona School of Informatics (Catalan: Facultat d'Informàtica de Barcelona)
Fires brigade, of the United States Army
International Federation for Structural Concrete (French: Fédération Internationale du Béton)
United Nations Force Intervention Brigade
Federal Investigation Bureau, parody of the Federal Bureau of Investigation in the Grand Theft Auto video game series
Friendly Illinois Buddy, an exonym used by Wisconsinites to refer to Illinoisans