People in every English-speaking country use the word "ain't". At least the major English-speaking ones like Canada, the U.S., the U.K., Australia and New Zealand.
England was it's birthplace. It sort of evolved over time as a way to combine "am I not", "are you not," "isn't it" and so forth. But it goes back a long way, at least to the 1600s. Even though it's considered bad speech, "ain't" as a word has quite a proud and literary history.
Satisfied your curiosity about it, did I? ;-)
we do here in the uk...i use it quite a lot
I know Canadians do as I ain't American I am Canadian! Probably the US does too
We do! I'm in the USA, so I would know ;)
ain't got no clue
Other than the US, I ain't got any idea.