Bette Davis Almost Passed on the Greatest Role of Her Career —The Reason Why Is Wild
Even after Bette Davis was cast in All About Eve, many people involved in the production made it clear they didn't want her in the role.

There are some roles that truly seem made for certain actors. From Jimmy Stewart as George Bailey to Ian McKellen as Gandalf, it almost seems sacrilegious to entertain the notion of anyone else stepping into these roles. Nowhere is this notion more prevalent than Bette Davis as Margo Channing in All About Eve. Often considered one of the finest and most literate films ever made, All About Eve remains a beloved and influential picture, which is in large part due to Davis. Played with both a clever realism and a fulfilling larger-than-life personality, Davis, whose versatility on the screen cannot be understated, really created something special with Margo. It remains her greatest legacy, so it may come as something of a surprise that she wasn’t the first choice to play the part. And even once she was cast, nearly everyone involved (and even those with no relation to the film) made it clear that they were against Davis playing the part.