Clint Eastwood has revealed he turned down the chance to appear in Sergio Leone's 1984 gangster epic Once Upon a Time in America, a film now widely regarded as a masterpiece. It marks another instance of Eastwood declining a major project, having previously also passed on Francis Ford Coppola's Apocalypse Now and two other Leone films, Once Upon a Time in the West and Duck You Sucker!, despite Leone having launched Eastwood's film career via the Dollars trilogy.

Eastwood explained that Leone first floated the idea of him playing an Irish gangster as far back as the making of The Good, the Bad and the Ugly, but the concept never developed into a concrete script or plan, remaining vague for years while Leone took over a decade to bring it to the screen. Eastwood said he needed certainty before committing to any project, remarking "I like to know the joke… I don't want someone to tell me a joke and not give me the punchline," and so declined without Leone ever providing that clarity.