Argentine Messi has won the award, formerly known as World Player of the Year, for the past three years and is favourite again after more goal-scoring exploits.
Messi and the equally prolific Ronaldo often divide opinion over who is the superior player and this year has been no different as they appear to push each other to even greater heights on a weekly basis.
Ronaldo's manager at Real Madrid, Jose Mourinho, recently said it would be a crime if his player did not win the Ballon d'Or for a second time, after comments from Barcelona's coach Tito Vilanova describing Messi as the "greatest player in the world, by a long way".
"If Messi is the best on the planet, Ronaldo is the best in the universe. It would be a crime if Ronaldo did not win the Ballon d'Or," Mourinho said in October, shortly after the Portugal international became the first player to score in six consecutive 'Clasicos.'
Messi scored 50 goals in La Liga last season, four more than Ronaldo, and has scored 82 in the calendar year so far, three short of the record of 85 by Gerd Muller in 1972.
However, 2008 winner Ronaldo was instrumental in Real Madrid's Spanish league title last season and helping Portugal reach the semi-finals of the European Championship.
Iniesta is the only one of the three candidates to have won a World Cup as well as two European Championship with Spain.
Should Messi win the award in Zurich on Jan. 7 he would become the first player to win it four times.
The candidates for Coach of the Year are Spain's Vicente del Bosque, former Barcelona coach Pep Guardiola and Mourinho.
Alex Morgan and Abby Wambach of the United States and Brazil's Martha were the nominations for the FIFA women's World Player of the Year prize.
The nominations come from a poll in which the captains and head coaches of the men's and women's national teams, as well as selected media, vote for candidates.
