The 23-year-old Portugal and Manchester United winger received 935 votes in a worldwide poll of national team captains and coaches, with the results announced by Brazil's all-time great Pele.
Lionel Messi, the Barcelona and Argentina midfielder, was runner-up with 678 votes, while Liverpool striker Fernando Torres was third with 203.
Ronaldo scored 42 goals last season, leading Manchester United to the Premier League and Champions League titles in May.
"It is an overwhelming moment, a very special moment in my life," Ronaldo said. "I would like to say to my mother and sister that the fireworks can be fired off now."
Brazil's Marta won the women's award for the third year in a row.
Ronaldo previously won the Ballon D'Or as European player of the year and World Soccer magazine's player of the year award.