The 26-year-old 'High School Musical' star, who sought treatment in early 2013 after struggling with alcoholism and substance abuse, moved up three places to grab the title.
The annual poll was held by Heat magazine, which saw diver and television personality, Tom Daley, on the second place followed by ace footballer David Beckham in the 101 Hottest Hunks list.
Users of the magazine's website voted in thousands and selected Efron as the hottest man alive, said its editor-in-chief.
The magazine said Efron's topless appearance in the movie 'Bad Neighbours', along with having his shirt ripped off by Rita Ora at the MTV Awards, had secured his place at number one.
The highest new entry in the list is of actor Jamie Dornan on the eighth place. The actor will be seen in the screen adaptation of 'Fifty Shades Of Grey' next year.