Yes, according to an interview with Hero Complex, the "Dirty Harry" star was considered for the title role in 1978's "Superman" — a role that eventually went to Christopher Reeve.
"I can remember – and this was many years ago – when [Warner Bros. President] Frank Wells came to me about doing Superman," said Eastwood. "So it could have happened. This was when they first started to think about making it. I was like, 'Superman? Nah, nah, that’s not for me.' Not that there’s anything wrong with it. It’s for somebody, but not me."
Richard Donner's big-screen take on the Man of Steel eventually took flight with another actor, but Eastwood said he wasn't interested in the role then or later, drawn instead toward roles he felt were more "grounded."
“I always liked characters that were more grounded in reality," he said. "Maybe they do super things or more-than-human things — like Dirty Harry, he has a knack for doing crazy things, or the western guys — but, still, they’re not caped crusaders."
Superhero typecasting was also a concern, according to the veteran actor and filmmaker.
"That was part of the consideration, a big part,” he said. “Look at Reeve, he was excellent. That was a big factor. You get a role like that, and it locks you in a bit. True, I had the western genre and the ‘Dirty Harry’ role, but everybody made westerns and did cop movies; they didn’t seem as bad [for typecasting the actors]."
And in a bit of a surprise turn, Eastwood name-dropped the one superhero he was a big fan of: Marvel's sea-dwelling Sub Mariner, Namor.
"The Sub-Mariner, that’s the one I always liked," he said. "I had all of those comics when I was a kid."