| Flagship | Flam | Flambeau, Price County, Wisconsin |
| Flambeau, Rusk County, Wisconsin | Flame | Flame (malware) |
| Flame Nebula | Flame test | Flame Towers |
| Flamethrower | Flammability | Flammulina velutipes |
| Flamsteed designation | Flamurtari Vlorë | Flanagan, Illinois |
| Flandreau, South Dakota | Flange | Flank |
| Flank gland | Flanvotumab | Flap |
| Flap endonuclease | Flappy Bird | Flaps |
| Flare | Flare (countermeasure) | Flare (phone) |
| Flare gun | Flare star | Flash (comics) |
| Flash (photography) | Flash Airlines Flight 604 | Flash evaporation |
| Flash memory | Flash Memory | Flash mob |
| Flash point | Flash prose | Flash Video |
| Flashback (narrative) | Flashdance | Flasher, North Dakota |
| FlashForward | FlashFXP | Flashlight |
| FlashNotes | Flat (music) | Flat feet |
| Flat glass | Flat organization | Flat panel display |
| Flat Rock, Henderson County, North Carolina | Flat Rock, Illinois | Flat Rock, Michigan |
| Flat tax | Flatberg | Flatbergium sericeum |
| Flatbread | Flatfish | Flatland |
| Flatness (systems theory) | Flatonia, Texas | Flattening |
| Flatulence | Flatwoods, Kentucky | Flatwoods, West Virginia |
| Flavia Pennetta | Flavin adenine dinucleotide | Flavin mononucleotide |
| Flavio Cipolla | Flavio Roma | Flaviviridae |
| Flavivirus | Flavobacteria | Flavobacteriaceae |
| Flavobacteriales | Flavobacteriia | Flavones |
| Flavonoid | Flavored milk | Flavour (particle physics) |
| Flax | Flaxton, North Dakota | Flaxville, Montana |
| Flaying | Flávio Amado | Flávio Saretta |
| Fläschenspitz | Fléchin | Flórián Albert |
| Flüela Schwarzhorn | Flüela Wisshorn | Flügel |
| Flea | Flecainide | Fleckistock |
| Fleet Satellite Communications System | Fleischmanns, New York | Fleming's left-hand rule for motors |
| Fleming's right hand rule | Fleming, Colorado | Fleming, New York |
| Fleming-Neon, Kentucky | Flemingsburg, Kentucky | Flemington, Georgia |
| Flemington, Missouri | Flemington, West Virginia | Flemish Community |
| Flemming Povlsen | Flensburg Government | Flensburg, Minnesota |
| Flerovium | Flers, Pas-de-Calais | Fletcher, North Carolina |
| Fletcher, Ohio | Fletcher, Oklahoma | Fletcher, Vermont |
| Fletschhorn | Fleur-de-lis | Fleurbaix |
| Fleury Di Nallo | Fleury, Pas-de-Calais | Flevoland |
| Flexbourg | Flexible manufacturing system | Flexiviridae |
| Flexor carpi radialis muscle | Flexor carpi ulnaris muscle | Flexor digiti minimi brevis muscle (hand) |
| Flexor digitorum profundus muscle | Flexor digitorum superficialis muscle | Flexor pollicis brevis muscle |
| Flexor pollicis longus muscle | FlexRay | Flextime |
| FLG-AS1 | Flibanserin | FLiBe |
| Flickr | Flickr.com | Flicky |
| Flight (2012 film) | Flight 19 | Flight and expulsion of Germans (1944–50) |
| Flight attendant | Flight control surfaces | Flight dynamics (fixed-wing aircraft) |
| Flight engineer | Flight feather | Flight instrument |
| Flight International | Flight recorder | Flight simulator |
| Flight suit | Flight test | FlightGlobal |
| Flightglobal | Flightglobal.com | Flightplan |
| Flikken Maastricht | Flimspitz | Flinders Petrie |
| Flint | Flint Township, Michigan | Flint, Michigan |
| Flip-flop (electronics) | Flip-flops | Flipped classroom |
| Flippin, Arkansas | Flirtation Walk | Flirting |
| FLN football team | Floater | Floating Bridge, Dubai |
| Floating point | Floating point unit | Floating ribs |
| Floating-point unit | Floatplane | Flocculation |
| Flock | Flock (birds) | Flock (web browser) |
| Flomoxef | Flood | Flood basalt |
| Flood control | Flood control in the Netherlands | Flood fill |
| Flood myth | Floodplain restoration | Floodwood, Minnesota |
| Floor | Floor (gymnastics) | Floor and ceiling functions |
| Floor area (building) | Floor plan | Floor plate |
| Floppy disk | FLOPS | Flora of Azerbaijan |
| Flora of China | Flora, Illinois | Flora, Indiana |
| Flora, Mississippi | Floral design | Floral Genome Project |
| Floral Magician Mary Bell | Floral Park, New York | Florence |
| Florence (town), Wisconsin | Florence Arthaud | Florence Chadwick |
| Florence County, Wisconsin | Florence Delay | Florence Devouard |
| Florence flask | Florence Griffith Joyner | Florence Nightingale |
| Florence Nightingale effect | Florence Township, Michigan | Florence Welch |
| Florence, Arizona | Florence, Colorado | Florence, Illinois |
| Florence, Kansas | Florence, Kentucky | Florence, Minnesota |
| Florence, Mississippi | Florence, New York | Florence, South Carolina |
| Florence, South Dakota | Florence, Texas | Florencia Peña |
| Florencio Sánchez | Florent Balmont | Florent Laville |
| Florent Malouda | Florent Marty | Florent Piétrus |
| Florent Pietrus | Florent Rouamba | Florent Serra |
| Florent Sinama Pongolle | Florentin Petre | Florentin Pogba |
| Florentin Smarandache | Floresville, Texas | Florian Bague |
| Florian Fromlowitz | Florian Heller | Florian Klein |
| Florian Koch | Florian Kringe | Florian Marange |
| Florian Maurice | Florian Mayer | Florian Meyer |
| Florian Pittiș | Floriano Peixoto | Floriculture |
| Florida | Florida Championship Wrestling | Florida Film Festival |
| Florida Institute of Technology | Florida, Massachusetts | Florida, Missouri |
| Florida, Montgomery County, New York | Florida, Ohio | Florin Gheorghiu |
| Florin Piersic | Florin Prunea | Florin Răducioiu |
| Florinda Bolkan | Floringhem | Floris, Iowa |
| Flossmoor, Illinois | Flour | Flour treatment agent |
| Flous | Flovilla, Georgia | FLOW |
| Flow control (data) | Flow cytometry | Flow karyotyping |
| Flow sensor | Flowchart | Flower |
| Flower Hill, New York | Flower Mound, Texas | Flower of Life |
| Flowerfield Township, Michigan | Flowering plant | Flowery Branch, Georgia |
| Flowood, Mississippi | Floyd Ayité | Floyd Bennett |
| Floyd County, Indiana | Floyd E. Bloom | Floyd Mayweather, Jr. |
