"I'm marrying up," said the Oscar winning actor about his fiancé of three months.
The Gravity star also discussed his recent feud with British tabloid The Daily Mail during his interview, telling the magazine "it's just fun to slap those bad guys every once in a while, knock 'em around."
"Usually the argument is: 'Hey, we're not gonna tell you our source,' and, 'Prove it.' And when they actually do it themselves it's so great," Clooney said. "You go, 'OK, well you obviously just screwed this [up], so I think I can get you now."
The actor added that as a celebrity it's important to "pick your fights at a tabloid" because "every day they write things that aren't true."
"But every once in a while they write something that is actually dangerous to your family, and it's probably not true. And that's the one you pick," he concluded.
Clooney will reportedly marry Alamuddin in the Downton Abbey castle. There's no word on the date of the nuptials.