Who almost played the role of Indiana Jones instead of Harrison Ford?

The answer is: Tom Selleck. When you see Tom Selleck, you wonder: Is he wearing the mustache, or is the mustache wearing him?OK, maybe that’s just me, but you probably DON’T think: “Hey that guy looks like an adventuring professor!” Yet he very nearly was. In fact, he was already cast as Indiana Jones, but his contract with Magnum P.I. kept him from being able to be in the movie. And Harrison Ford doesn’t take the near miss lightly, publicly stating: "I became the second choice, and I’m very grateful for Tom. Thank you, Tom, man.”Source