FIM may refer to:
- Facing Identification Mark, bar code designed by the United States Postal Service to assist in the automated processing of mail
- Federated Identity Management, information technology term
- Fédération Internationale de Motocyclisme (International Motorcycling Federation), governing body of motorcycle racing
- Field ion microscope, type of microscope that can be used to image the arrangement of atoms at the surface of a sharp metal tip
- Finnish markka, the ISO 4217 code for the former currency of Finland
- First-in-man study, clinical trial where a medical procedure is tested on human subjects for the first time
- Fisher information matrix, the matrix form of Fisher information
- Flight interruption manifest, document issued by an airline for rerouting passengers
- Forefront Identity Manager, state-based identity management software product from Microsoft
- Institute for Mathematical Research (FIM, Forschungsinstitut für Mathematik located at ETH Zurich)
- Fox Interactive Media, former name of News Corp. Digital Media
- Frente Independiente Moralizador (Independent Moralizing Front), former Peruvian political party
- Friendship Is Magic, the current incarnation of the My Little Pony animated series.
- The US Military designation for a shoulder-launched, intercept guided missile. Examples include the FIM-92 Stinger missile and the FIM-43 Redeye.
- Functional Independence Measure, a standardized assessment tool used by physical and occupational therapists.