What's that got to do with the price of fish?
English • United Kingdom
Used when someone says something completely irrelevant to the conversation. The fixed phrase is "What's that got to do with the price of ___" but the item could be fish, bacon, chips, or many other things.
"What do you think about the new sports centre?" "Ye I think the weather has been quite good today." "What's that got to do with the price of fish? I was talking about the sports centre."