The Australian Olympic swimming champion, who used to date fellow athlete Stephanie Rice, said that he was surprised to have been voted the most eligible male celebrity in the country.
After being presented with his award and a prize of a Nissan Micra by actress and singer Sophie Monk, Sullivan told The Daily Telegraph: "Odds aren't usually the best indicator, I would have gone with [Home and Away star] Dan Ewing."
Female celebrities attending the James Bond-themed event at The Ivy in Sydney included model April Rose Pengilly, TV star Laura Csortan and designer Ruby Rose.
The other nominees, who were announced last month, included ironman Caine Eckstein, radio host Ash Williams, DJ Chris Stafford, AFL footballer Josh Kennedy and TV presenter and actor Scott McGregor.
Last year's champion was Underbelly actor Firass Dirani, who said he was "happy" to win. Other past winners have included soap star Axle Whitehead, presenter Andrew Gunsberg and comedian Andy Lee.