In All About Eve as Margo Channing who advises Fasten your seat belts going to be a bumpy night?

It's Margo Channing, played by Bette Davis, who utters the famous line "Fasten your seat belts, it's going to be a bumpy night" in the film *All About Eve*.

This iconic quote is not directly addressed to anyone in particular, but it's spoken in the context of Margo's tumultuous life and the drama that's about to unfold.