The Australian hunk was named the winner of the annual accolade at a star-studded bash in New York City on Monday (05Mar12).
Explaining their choice, Cosmo bosses state, ""Just as Russell Crowe and Brad Pitt are getting a little too old to fulfill our hottie-action-hero fantasies, along comes 35-year-old Sam Worthington. Our crush kicked in when the Aussie actor played a soldier with a heart of gold in Avatar and gained momentum as he showed off more skin and grit in Clash of the Titans. By the time he portrayed a Nazi-hunting secret agent in The Debt this past August, we were sold on him as our Fun Fearless Male of the Year.""
Worthington's fellow Aussies Liam Hemsworth and Rose Byrne also picked up prizes at the ceremony, as did funnymen Jonah Hill and Paul Rudd, actresses Zoe Saldana and Freida Pinto, and country star Blake Shelton.
Worthington follows in the footsteps of British funnyman Russell Brand, who scooped the Fun Fearless honour last year (11).
Singers John Mayer and Nick Lachey and actors Patrick Dempsey and Josh Duhamel are also previous recipients.