Matt Damon, that's who, according to People magazine.
This is the 23rd year the publication has bestowed that title.
Last year, George Clooney took it, for the second time. The first winner? Mel Gibson in 1985.
People staff writer Ericka Souter gave all the buzz behind the latest selection on The Early Show Wednesday.
Others in the running included David Beckham, Brad Pitt, Patrick Dempsey (of "Grey's Anatomy"), Jake Gyllenhaal, Matthew McConaughey, Justin Timberlake, Shemar Moore (of "Criminal Minds"), Taye Diggs (the stage and screen actor/singer), Gerard Butler (of "300"), and Josh Bernstein (of "Josh Bernstein's Adventures," Discovery Channel).
Souter explained that readers let People know who they think is sexy, and editors take that into consideration. People editors have their favorites, too. They sit around a table and discuss it, and, she kidded, they all "dread" looking at pictures of the gorgeous!
She also revealed an unusual turn of events for People: When Damon learned he was chosen -- he turned them down! Damon wrote People a "fabulous" letter explaining that he doesn't normally talk about his personal life. He said he was blushing when he read that he had been picked. While he got a huge kick out of the nod, he didn't feel worthy, he said. "You just gave an aging suburban dad ego boost of a lifetime," he wrote.
But People persisted, and decided Damon was still its "Man." In fact, the letter ended up backfiring for Damon -- since it reflected all the things People's editors love about him, including his "irresistible sense of humor," his dedication to his family, and his "heart-melting humility." Damon wound up giving People permission to reprint the letter, in this week's issue.
People also talked to friends of Damon who'd held the title of "Sexiest Man." The 2002 winner, Ben Affleck, told the magazine what a great guy Damon is. And last year's winner, Clooney, joked with People that, while he's reluctant to give up the crown, he and Pitt have been campaigning for Damon for years.
Meanwhile, who does Damon think should be named Sexiest Man Alive? In his letter to People, the actor suggested New England Patriots quarterback Tom Brady. Brady's response? "Matt and I always argue about who's sexier!"
To see all of Souter's comments, on Damon and the others,