FFI may refer to:
Entertainment
- Festival Film Indonesia, Indonesia
- Final Fantasy (video game), or Final Fantasy I, 1987
- Final Fight (video game), 1989
Language
- Ligature_(writing)#Stylistic_ligatures|, a typographical ligature
- Foia Foia language, spoken in Papua New Guinea
Organizations
- Family Firm Institute
- Fauna and Flora International, a conservation group
- Fellow of the Flag Institute
- Film Federation of India
- Finlay Forest Industries, a defunct Canadian forest products company
- Franciscan Friars of the Immaculate, a Roman Catholic institute of religious life
- Frederikshavn fI, a Danish sport club
- Free File, Inc., an American consortium of tax preparation companies
- French Forces of the Interior (French: '), French resistance fighters during World War II
- Fuel Freedom International, an American multi-level marketing company
- Norwegian Defence Research Establishment (Norwegian: '), a Norwegian military R&D institute
Science and technology
- Fatal insomnia, a fatal neurological disorder
- Foreign function interface, in computing