| F | Farad - Fluorine | - | Astronomy |
| F | Femto | - | Astronomy |
| F&SF | (The Magazine Of) Fantasy & Science Fiction | - | Astronomy |
| F.K.A. OR F/K/A | Formerly Known As | - | Astronomy |
| F/U/B/O | For The Use And Benefit Of (found In Legal Documents) | - | Astronomy |
| F/W | Fixed Wing | - | Astronomy |
| FA | Field Artillery - Financial Aid - Football Association (England) | - | Astronomy |
| FA | Femtoampere | - | Astronomy |
| FA | Persian Language (ISO 639-1 Code) | - | Astronomy |
| FAA | U.S. Federal Aviation Administration - Financial Aid Administrator - Fleet Air Arm - Functional Area Analysis | - | Astronomy |
| FAAD | Forward Area Air Defence | - | Astronomy |
| FAADEZ | Forward Area Air Defence Engagement Zone | - | Astronomy |
| FAAN | Fellow Of The American Academy Of Nursing | - | Astronomy |
| FAAQ | Frequently Asked And Anticipated Questions (cf. FAQ) | - | Astronomy |
| FAASV | Field Artillery Ammunition Supply Vehicle | - | Astronomy |
| FAB | Feline Advisory Bureau (UK Feline Charity) | - | Astronomy |
| FAC | Forward Air Controller - Front Of Allies For Change - Frontal Affinity Chromatography - Full Aperture Calibrator | - | Astronomy |
| FACA | (US) Federal Advisory Committee Act | - | Astronomy |
| FACS | Formal Aspects Of Computing Science - Fluorescent-activated Cell Sorting | - | Astronomy |
| FACTS | Flexible Alternating Current Transmission System | - | Astronomy |
| FAD | Flavin Adenine Dinucleotide | - | Astronomy |
| FADAC | Field Artillery Data Computer | - | Astronomy |
| FAH | Federation Of American Hospitals - Fine Arts And Humanities - Foreign Affairs Handbook | - | Astronomy |
| FAI | F?d?ration A?ronautique Internationale (French | - | Astronomy |
| FAM | Foreign Affairs Manual | - | Astronomy |
| FAO | Food And Agriculture Organization | - | Astronomy |
| FAO | Faroese Language (ISO 639-2 Code) | - | Astronomy |
| FAQ | Frequently Asked Questions (sometimes Pronounced Fak) | - | Astronomy |
| FARC | Fuerzas Armadas Revolucionarias De Colombia (Spanish | - | Astronomy |
| FARP | Forward Arming And Refuelling Point / Forward Area Rearm/refuel Point | - | Astronomy |
| FAS | Federation Of American Scientists - Fetal Alcohol Syndrome | - | Astronomy |
| FAS | Persian Language (ISO 639-2 Code) | - | Astronomy |
| FASCAM | Field Artillery Scatterable Mines | - | Astronomy |
| FASD | Fetal Alcohol Spectrum Disorder | - | Astronomy |
| FASEB | Federation Of American Societies For Experimental Biology | - | Astronomy |
| FAT | Field Artillery Tractor - File Allocation Table | - | Astronomy |
| FAVS | Future Armoured Vehicle System | - | Astronomy |
| FBCB2 OR FBCB? | Force XXI Battle Command | - | Astronomy |
| FBCS | Fellow Of The British Computer Society | - | Astronomy |
| FBI | Federal Bureau Of Investigation | - | Astronomy |
| FBIDST | Fellow Of The British Institute Of Dental And Surgical Technologists | - | Astronomy |
| FBIS | Foreign Broadcast Information Service | - | Astronomy |
| FBR | Fast Breeder Reactor - Foundation For Biomedical Research | - | Astronomy |
| FC | Fire Control -Funnel Cloud (METAR Code) | - | Astronomy |
| FC | Femtocoulomb | - | Astronomy |
| FCA | Fraction Of Combat Active Forces | - | Astronomy |
| FCC | U.S. Federal Communications Commission | - | Astronomy |
| FCE | First Certificate In English | - | Astronomy |
| FCM | Federation Of Canadian Municipalities - Fogarty's Cove Music | - | Astronomy |
| FCO | UK Foreign And Commonwealth Office | - | Astronomy |
| FCS | Future Combat System | - | Astronomy |
| FCW | Florida Championship Wrestling | - | Astronomy |
| FCZ | Forward Combat Zone | - | Astronomy |
| FDA | Food And Drug Administration (U.S.) | - | Astronomy |
| FDC | Federal Detention Center (U.S.) - Fire Direction Centre | - | Astronomy |
| FDDI | Fibre Distributed Data Interface | - | Astronomy |
| FDR | Flight Data Recorder - Franklin Delano Roosevelt | - | Astronomy |
| FE | Fully Exposed (armoured Vehicle Target | - | Astronomy |
| FE | Iron (Latin Ferrum) | - | Astronomy |
| FEAR | First Encounter Assault Recon - False Evidence Appears Real | - | Astronomy |
| FEAST | Forum For European-Australian Science And Technology Cooperation | - | Astronomy |
| FEBA | Forward Edge Of The Battle Area | - | Astronomy |
| FEC. | Fecit (Latin | - | Astronomy |
| FED | Field Emission Display | - | Astronomy |
| FEDEP | Federation Development Process (Simulation) | - | Astronomy |
| FEF | Frontal Eye Field (neurophysiology) | - | Astronomy |
| FEMA | U.S. Federal Emergency Management Agency | - | Astronomy |
| FENS | Federation Of European Neuroscience Societies | - | Astronomy |
| FEP | Firepower Enhancement Program - Fleet Satellite (FLTSAT) Extremely High Frequency (EHF) Package | - | Astronomy |
| FES | Flywheel Energy Storage | - | Astronomy |
| FET | Field-Effect Transistor | - | Astronomy |
| FEZ | Fighter Engagement Zone | - | Astronomy |
| FF | Final Fantasy | - | Astronomy |
| FF | Femtofarad | - | Astronomy |
| FF | Fula Language (ISO 639-1 Code) | - | Astronomy |
| FFA | Forum Fisheries Agency -Free-Fire Area - Fusiform Face Area - Football Federation Australia - Future Farmers Of America (today The National FFA Organization) | - | Astronomy |
| FFC | Free For Chat | - | Astronomy |
| FFE | Fukuoka Futures Exchange | - | Astronomy |
| FFF | F?d?ration Fran?aise De Football (French | - | Astronomy |
| FFG | Guided Missile Frigate (hull Classification Symbol) | - | Astronomy |
| FFOV | Forward Field Of View | - | Astronomy |
| FFR | Fédération Française De Rugby (French Rugby Federation) | - | Astronomy |
| FFS | For Fuck's Sake | - | Astronomy |
| FFT | Fast Fourier Transform - Final Fantasy Tactics | - | Astronomy |
| FG | Femtogram | - | Astronomy |
| FG | Fog (METAR Code) - French Guiana (FIPS 10-4 Territory Code) | - | Astronomy |
| FH | Femtohenry | - | Astronomy |
| FHFIF | Foster's Home For Imaginary Friends | - | Astronomy |
| FHI | Family Health International | - | Astronomy |
| FI | Finland (ISO 3166 Digram; FIPS 10-4 Country Code) | - | Astronomy |
| FI | Finnish Language (ISO 639-1 Code) | - | Astronomy |
| FIA | F?d?ration Internationale De L'automobile (French International Automobile Federation) | - | Astronomy |
| FIAT | Fabbrica Italiana Automobili Torino (Italian Italian Car Factory Of Turin) | - | Astronomy |
| FIB | Fucking Illinois Bastard (Wisconsin Slang | - | Astronomy |
| FIBA | F?d?ration Internationale De Basketball Amateur (French | - | Astronomy |
| FIBUA | Fighting In Built-Up Areas | - | Astronomy |
| FIC | Fellowship For Intentional Community | - | Astronomy |
| FID | Foreign Internal Defence | - | Astronomy |
| FIDÂ | F?d?ration Internationale Des ?checs (French World Chess Federation) | - | Astronomy |
| FIE | Fly-In Echelon | - | Astronomy |
