Co-founder and CEO, Airbnb
40 Under 40 rank: 17
Soon after graduating from the Rhode Island School of Design, Chesky moved to San Francisco to be a designer -- but a billion-dollar idea intervened. A Valley neophyte at the time ("Someone was talking about angels, and I was like, 'Oh, my God, I don't believe in angels -- these people are totally crazy,' " Chesky told Fortune), he's now the ultimate insider, taking meetings with the likes of Warren Buffett and Jeff Bezos. He still sketches from time to time, as he's doing here at Brainwash, the café he and his co-founders, Joe Gebbia and Nate Blecharczyk, "camped out in all day" when they were starting Airbnb. "In hindsight those days are nostalgic and romantic," he says. "But at the time it wasn't at all. It was actually very scary."
Who are 2012's young business stars? We've got the CEO of a blue-chip beer brand, an airline CEO who just placed the largest order in commercial aviation history, and Warren Buffett's new prodigy, among the Silicon Valley hotshots and others.