FD or similar may refer to:
Science and technology
- Canon FD lens mount, a standard for connecting a lens to a camera
- Familial dysautonomia, a disorder of the autonomic nervous system
- Fermi–Dirac statistics (F–D statistics), in quantum statistics
- Ferredoxin, iron–sulfur proteins
- File descriptor, in Unix and related computer operating systems
- Freedesktop.org (fd.o), an interoperability project
- Functional dependency, a constraint in a relation from a database
- Nissan FD engine, for trucks and buses
Transportation
- Thai AirAsia, IATA airline code FD
- Mazda RX-7 (FD), a car
- FD Phantom, original name for the FH Phantom jet fighter
- Russian locomotive class FD
- Flight director (aeronautics), a flight instrument
- Flying Dutchman (dinghy)
Other uses
- Formula Drift, an American motorsport series
- Fidei defensor (Latin, 'Defender of the Faith'), part of the full style of many English/British monarchs
- Fixed deposit, a financial instrument
- Finance Director, or chief financial officer, in a company
- Fire Department, providing firefighting services
- Force of the Right (Forța Dreptei), a Romanian political party
- Financial Dynamics, a UK business services and lobbying firm acquired by FTI Consulting in 2006
See also
- Floppy disk drive (FDD) in early computers