Clint Eastwood could have played the Man of Steel in Richard Donner’s Superman movie. Reeve was ultimately cast instead, but he was far from the first choice to play the character. Long before the studio offered the part to Reeve, it had its eye on Clint Eastwood, who was one of the biggest stars in Hollywood and had been for quite some time.

https://screenrant.com/clint-eastwood-superman-movie-role-turned-down/