| watch one's mouth | | | |
| watch the world burn | | | |
| waterfowl alignment | | | |
| water under the bridge | | | |
| wave goodbye | | | |
| wayback | | | |
| WD-40 | | | |
| weaponized incompetence | | | |
| wear rose-colored glasses | | | |
| wear too many hats | | | |
| weather the storm | | | |
| weed out | | | |
| we haven't got all day | | | |
| weight of the world | | | |
| well and good | | | |
| well-oiled | | | |
| Welsh-comb | | | |
| wet-blanket | | | |
| wet one's beak | | | |
| wet the shamrock | | | |
| what are the odds | | | |
| what do you say | | | |
| whatever it takes | | | |
| what in time | | | |
| what not | | | |
| what's eating | | | |
| what's it to you | | | |
| what's the difference | | | |
| what's the story, bud | | | |
| what the Devil | | | |
| what with | | | |
| wheel out | | | |
| when Hell freezes over | | | |
| when pigs fly | | | |
| when two Sundays come together | | | |
| where's the fire | | | |
| while we're young | | | |
| whip the cat | | | |
| whisk away | | | |
| whistle Dixie | | | |
| whistle past the graveyard | | | |
| white coat hypertension | | | |
| white magic | | | |
| white rabbit | | | |
| white trash | | | |
| whole ball of wax | | | |
| whole package | | | |
| whoop ass | | | |
| who's 'she', the cat's mother | | | |
| why in the world | | | |
| wide awake | | | |
| widow-maker | | | |
| willful ignorance | | | |
| willy-nilly | | | |
| wind back the clock | | | |
| window-shopping | | | |
| winged word | | | |
| win one for the Gipper | | | |
| win the battle, but lose the war | | | |
| wipe someone's nose | | | |
| wise apple | | | |
| with a grain of salt | | | |
| with an eye towards | | | |
| with a will | | | |
| wither on the vine | | | |
| within an ace of | | | |
| with no further ado | | | |
| with one's head held high | | | |
| without a hitch | | | |
| with pleasure | | | |
| woe betide | | | |
| wolf in one's stomach | | | |
| woman of few words | | | |
| wombat-headed | | | |
| word is bond | | | |
| word on the street | | | |
| word to the wise | | | |
| working girl | | | |
| work like a dream | | | |
| work one's magic | | | |
| work spouse | | | |
| work with one's hands | | | |
| world record | | | |
| worm's-eye view | | | |
| worship the ground someone walks on | | | |
| worst-kept secret | | | |
| worth one's salt | | | |
| woulda, coulda, shoulda | | | |
| wag a finger | | | |
| wait for Godot | | | |
| wait for it | | | |
| wait for the other shoe to drop | | | |
| waiting game | | | |
| wait on someone hand and foot | | | |
| wait on someone hand, foot and finger | | | |
| wait upon hand and foot | | | |
| wake the dead | | | |
| wake up on the wrong side of bed | | | |
| walk all over | | | |
| walk away | | | |