The Maroon 5 frontman, who beat off stiff competition from the likes of 'Luther' actor Idris Elba, singer Justin Timberlake and retired soccer star David Beckham to the prestigious title, says his wife-to-be, Victoria's Secret model Behati Prinsloo, found it amusing.
'The Voice' US judge told People magazine her reaction was: "Laughter, a lot of laughter," adding: "She's keeping me humble."
On Tuesday night's (19.11.13) episode of 'The Voice', host Carson Daly announced Adam's big win to the studio audience, much to the singer's embarrassment.
The 34-year-old hunk said he shared the news with Behati by saying: "Hey, how ya doing? Let's go to dinner tonight. And People magazine says I'm the Sexiest Man Alive."
Adam - who takes the title from 2012's winner Channing Tatum - also said about his win: "As a musician, you have fantasies that you want to win Grammys, but I didn't really think that this was on the table. I was just amazed and stunned and it almost seemed like they were kidding, but they weren't, so that's cool."
The singer also confessed he was looking forward to settling down with his fiancée, after popping the question in July.
He said: "I didn't think marriage was for me for a long time. I was ready when I was ready. That's about as simple as it could possibly be."