He beat Germany goalkeeper Manuel Neuer and four-time winner Lionel Messi in a vote of national team captains and coaches from FIFA's 209 member countries, plus selected journalists.
Ronaldo retained football's highest individual honour after scoring 61 goals for Real Madrid and Portugal last year.
His record tally of 17 in a Champions League season helped his club win an unprecedented 10th European Cup title.
Ronaldo was more composed for this widely expected victory than during his tearful acceptance speech one year ago when ending Messi's four-year reign.
In the women's award, Germany midfielder Nadine Kessler beat Marta of Brazil and United States forward Abby Wambach.