Be game
Be hand in hand
Be into (something)
Be laid up
Be of the persuasion that (something) is so
Be off
Be off on the wrong foot
Be off to a bad start
Be that as it may
Be the case
Be the death of (someone)
Be to blame
Be/have something going for (one)
Bean counter
Bear (someone or something) in mind
Bear (something) out
Bear fruit
Bear in mind
Bear one's cross
Bear the brunt of (something)
Bear with (someone or something)
Bear witness (to something)
Bear/hold a grudge (against someone)
Beat (someone) to the punch/draw
Beat (something) into (someone's) head
Beat a hasty retreat
Beat a path to (someone's) door
Beat around the bush
Beat one's brains out
Beat one's head against the wall
Beat the clock
Beat the gun
Beat the living daylights out of (someone)
Beat the rap
Beat the tar out of (someone)
Beat up (someone)
Becoming on/to (someone)
Beef up (something)
Before long
Beg the question
Beg to differ with (someone)
Begin to see the light
Behind (someone's) back
Behind closed doors
Behind in/on (something)
Behind one's back
Behind schedule
Behind the eight ball
Behind the scenes
Behind the times
Belabor the point
Believe one's ears
Believe one's eyes
Below average
Below par
Belt (something) out
Bend (someone's) ear
Bend over backwards (to do something)
Bent on doing (something)
Beside oneself (with something)
Beside the point
Best bib and tucker
Best-laid plans of mice and men
Best/better part of (something)
Bet on the wrong horse
Bet one's boots
Bet one's bottom dollar
Better off
Between a rock and a hard place
Between the devil and the deep blue sea
Betwixt and between
Beyond a reasonable doubt
Beyond a shadow of a doubt
Beyond measure
Beyond one's depth
Beyond one's means
Beyond the pale
Beyond words
Bid adieu to (someone or something)
Bide one's time
Big cheese
Big cheese/gun/wheel
Big enchilada
Big fish in a small pond
Big frog/fish in a small pond
Big of (someone)
Big shot
Bigmouth
Bigwig
Binge and purge
Bird brain
Bird in hand is worth two in the bush
Bird in the hand is worth two in the bush
Birds and bees
Birds of a feather flock together
Birds-eye view
Birthday suit
Bite (someone's) head off
Bite off more than one can chew
Bite one's nails
Bite one's tongue
Bite the bullet
Bite the dust
Bite the hand that feeds (someone)
Bite the hand that feeds one
Bitten by (some kind of) bug
Bitter pill to swallow
Black and blue