- Yada yada
- Year dot
- Yellow-belly
- Yellow Peril
- You are what you eat
- You can lead a horse to water but you can't make it drink
- You can lead a whore to culture but you can't make her think
- You can't get blood out of a stone
- You can't have your cake and eat it too
- You can't hold with the hare and run with the hounds
- You can't make a silk purse out of a sow's ear
- You can't see the wood for the trees
- You can't teach an old dog new tricks
- You get on my wick
- You look as if you've been dragged through a hedge backwards
- You'll wonder where the yellow went when you brush your teeth with Pepsodent
- Young man's fancy
- Young turk
- Your days are numbered
- Your money or your life
- Your name is mud
- You've never had it so good
- Zero tolerance
- Zig-zag