chalk and cheese

(like) ˌchalk and ˈcheese

(also as different as ˌchalk and ˈcheese) (British English, informal) very different: It’s hard to imagine that Mark and John are brothers — they’re like chalk and cheese.
See also: and, chalk, cheese

chalk and cheese

Two objects that although appearing to be similar are in fact different. Just as certain varieties of crumbly white cheese might at first glance resemble chalk, so for example, siblings who resemble each other might have completely different personalities. They would be said to be as different as chalk and cheese.
See also: and, chalk, cheese
References in periodicals archive ?
Mullen said: "There were a few names you would have wanted to dodge but I landed Dale and, although we are chalk and cheese, I'm happy enough.
Chalk and cheese that are trapped together in a metal box twice a day in traffic.
However, a loophole allows the chalk and cheese pair to re-enter the competitive world, the caveat being that they become the first malemale team.
Chalk and cheese plans THE Grimscar Valley and St Luke's developments at Crosland Moor are as different as chalk and cheese.
I think we get on so well because we're like chalk and cheese.
According to Border's article in the Daily Telegraph, he opined that the standard of bowling Warner will face in Africa and the conditions he would experience will be chalk and cheese to the challenges that await him in England.
Leeds' kicking game was chalk and cheese compared to ours.
Oh, chalk and cheese, Johnny-me-lad, chalk and cheese
Glyndwe r University's Professor Michael Scott said: "We've tried collaboration with traditional universities - it was chalk and cheese.
THEY are as different as chalk and cheese but Meydan and Thurles were bedfellows at the foot of the league table for exchange punters a week ago.
However, the public soon warmed to their chalk and cheese appeal, and the duo have provided many hours of must see TV thanks to several other hit talent searches.
CHALK AND CHEESE Paul Rust as Denis Cooverman and Hayden Panettiere as Beth Cooper.
Cheese and biscuits, port and Stilton, chalk and cheese.
The invaluable dictionary also gives several examples, suggesting that this contrast of chalk and cheese was a well-known proverb, for example,
Meanwhile Val plans to dump Ian after finally realising they're like chalk and cheese.