- Rabbit and pork
- Rack and ruin
- Rack your brains
- Rag-and-bone man
- Rag, tag and bobtail
- Raining cats and dogs
- Raining stair-rods
- Raise Cain
- Rank and file
- Raspberry tart
- Rat arsed
- Raze to the ground
- Razzle-dazzle
- Read between the lines
- Read the riot act
- Real McCoy
- Rearranging the deckchairs on the Titanic
- Red-handed
- Red-letter day
- Red herring
- Red in tooth and claw
- Red rag to a bull
- Red sky at night …
- Red tape
- Reduplicated phrases
- Religion is the opium of the people
- Rest on his laurels
- Revenge is a dish best served cold
- Rhyme nor reason
- Rhyming slang
- Richard of York gave battle in vain
- Richard the Third
- Riddle wrapped up in an enigma
- Ride a cock-horse to Banbury Cross
- Riding shotgun
- Riff-raff
- Riley
- Rings a bell
- Ring a ring o'roses, a pocketful of posies, atishoo, atishoo, all fall down
- Ring down the curtain
- Ring-fencing
- Ring the changes
- Rinky-dink
- Rise and shine
- Road less travelled
- Road apples
- Road rage
- Road to hell is paved with good intentions
- Roasted to a turn
- Rob Peter to pay Paul
- Rock and roll
- rocket science
- rod for your own back
- A rolling stone gathers no moss
- Roly-poly
- Romeo, Romeo, wherefore art thou Romeo?
- Rootin' tootin'
- Rose by any other name would smell as sweet
- Rose is a rose is a rose
- Rosie Lea
- Rough diamond
- Round Robin
- Route one
- Rub of the green
- Rule of thumb
- Rum do
- Rumpy-pumpy
- Run a mile
- Run amok
- Run of the mill
- Run out of steam
- Run rings around
- Run the gauntlet