- Face that launched a thousand ships
- Face the music
- Faff about
- Fag end
- Failing to plan is planning to fail
- Faint-hearted
- Fair and square
- Fair dinkum
- Fair exchange is no robbery
- Fair play
- Fair to Midland
- Fair to middling
- Fairy-tale ending
- Fait accompli
- Faith will move mountains
- Fall from grace
- Fall guy
- Fall off the back of a lorry
- Fall on your sword
- Familiarity breeds contempt
- Famous for fifteen minutes
- Famous last words
- Famous last words
- Fancy free
- Fancy pants
- Fanny Adams
- Far be it from me
- Far from the madding crowd
- Farmers
- Fashion victim
- fast
- Fast and loose
- Fast asleep
- fat of the land
- Fate worse than death
- Fathom out
- Feather in one's cap
- Fed up
- Feeding frenzy
- fell off the back of a truck
- Fell swoop
- Fellow traveller
- Felt his collar
- Female of the species is more deadly then the male
- Fend for yourself
- Fend off
- Fiddlesticks
- Fiddling while Rome burns
- Fie, fih, fo, fum, I smell the blood of an Englishman
- Field day
- Fifteen minutes of fame
- Fifth column
- Fifth estate
- Fight fire with fire
- Fight the good fight
- Filthy rich
- Finagle's Law
- Fine as frog's hair
- Fine words butter no parsnips
- Finger lickin good
- Fingers and thumbs
- First dibs
- First water
- First World
- Fish rot from the head down
- Fish or cut bait
- Fish out of water
- As fit as a butcher's dog
- Fit as a fiddle
- Fits and starts
- Fits to a tee
- Five o'clock shadow
- Fixer-upper
- Flash in the pan
- Flat out
- Flavor of the month
- Flesh and blood
- Flogging a dead horse
- Floozie in the jacuzzi
- Flotsam and jetsam
- Fly by night
- Fly by the seat of one's pants
- Fly in the ointment
- Fly off the handle
- Fly on the wall
- Foam at the mouth
- Fobbed off
- Fogey
- Folk Etymology
- Fool and his money are soon parted
- Fools rush in where angels fear to tread
- Fool's errand
- Fool's gold
- Fool's paradise
- Foot in the door
- Foot of our stairs
- For all intents and purposes
- For crying out loud
- For ever and a day
- For every thing there is a season
- For good measure
- For keeps
- For the birds
- For whom the bell tolls
- Forbidden fruit
- Foregone conclusion
- Forewarned is forearmed
- Forgive them for they know not what they do
- Fork out
- Forlorn hope
- Forty winks
- Foul play
- Four by two
- Four corners of the earth
- Frailty, thy name is woman
- Francis Grose
- Freeze the balls off a brass monkey
- Freezing temperatures
- French phrases
- Friday afternoon car
- Friend in need is a friend indeed
- Friends, Romans, Countrymen, lend me your ears
- Frog in the throat
- Frog's hair
- From pillar to post
- From sea to shining sea
- From strength to strength
- Fruits of your loins
- Fuddy-duddy
- Full Monty
- Full of p*** and vinegar
- Full tilt
- Full to the gunwales
- Funny farm
- Fuzzy wuzzy