- Walk free
- Walk the walk
- Walk the plank
- Walkie-talkie
- Walter Scott
- Warts and all
- Watch the birdie
- watched pot never boils
- Watching brief
- Wave a red rag to a bull
- Wax lyrical
- Wax poetic
- We are a grandmother
- We are not amused
- We few, we happy few, we band of brothers
- We have seen better days
- We know where you live
- Weakest link
- Wear the trousers
- Wear your heart on your sleeve
- Weasel words
- Wee-wee
- Well heeled
- Well read
- Wet behind the ears
- Wet blanket
- What a palaver
- What a piece of work is man
- What are you like?
- What football is all about
- What God has joined together let no man put asunder
- What part of no don't you understand?
- What the dickens
- What you see is what you get – wysiwyg
- What's in a name? That which we call a rose by any other name would smell as sweet
- What's not to like?
- What's up Doc?
- When in Rome, do as the Romans do
- When it comes to the crunch
- When pigs fly
- When the going gets tough, the tough get going
- When the s*** hits the fan
- Where there's muck there's brass
- Whet your appetite
- Which is which?
- Which witch is which?
- While you live, tell truth and shame the Devil!
- Whip round
- Whipper snapper
- Whipping boy
- Whistle and flute
- Whistle blower
- Whistle down the wind
- White as snow
- White bread
- White elephant
- Whole kit and caboodle
- Whole-hearted
- Whole nine yards
- Whole shebang
- Whoops-a-daisy
- Why does bread always fall butter side down?
- Why should the Devil have all the best tunes?
- Wick
- Wide berth
- Wild and woolly
- Wild goose chase
- Willy nilly
- Win hands down
- Win one for the Gipper
- wing and a prayer
- Wing it
- Winter draws on
- Wish you were here
- Wit's end
- With bated breath
- With bells on
- Without a shadow of a doubt
- Without let or hindrance
- Without so much as a by your leave
- Woe betide you
- Woe is me
- Wolf in sheep's clothing
- Woman needs a man like a fish needs a bicycle
- Woman's place is in the home
- Women and children first
- Wooden hill to Bedfordshire
- Word association football
- Word for word
- Word in edgeways
- Word in your shell-like
- Words coined by William Shakespeare
- Words ending in gry
- Worse for wear
- Worth one's salt
- Wotcher
- Wouldn't touch with a barge-pole
- Wreak havoc
- Writing is on the wall
- Wrong end of the stick
- Wrong side of the blanket