Midnight Cowboy (1969) was the first X–rated film to win Best Picture, and it's still the only one to have done so. But this is not a straightforward question; different films get different ratings in different countries.
For example, Bonnie and Clyde (1967) won Best Supporting Actress (Estelle Parsons) and Best Cinematography (Burnett Guffey). It was one of the first films to get the new R rating in the USA, but it was originally rated X in the UK. (This was reclassified as 18 in 1997, and this particular film was downgraded to 15 in 2008. For details, refer to IMDb.)
Any source that describes Midnight Cowboy as the first X–rated film to win an Oscar (or an Academy Award) is probably American.
I have found it surprisingly difficult to determine what actually was the first X–rated film to win an Oscar. Every website I've been referred to by Google seems to concentrate on Midnight Cowboy; some say it was the first to win Best Picture, but some do say it was the first to win an Oscar. As I've just demonstrated (I hope), this is not the case. It may be Bonnie and Clyde; or there may well be one I've missed.
So ... what was the first film that was X–rated in the UK, to win an Oscar? Can anyone enlighten me?
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