The 38-year-old won the hearts of the public this year thanks to her honest and fair judging comments and her victory with winner Matt Cardle.
She also became a role model for working mums after it emerged she popped backstage to breastfeed her baby son Ethan during ad breaks on the X Factor.
Dannii wrote an open letter to fans thanking them for their support, saying: “To win a second time in three years is incredible.
“[Over the next year] I’ll be doing stuff with my fashion range Project D, a few new chapters for the paperback of my book and X Factor, I hope.”
Popular Dannii managed to pull a whopping 40.83% of readers votes. Boybands JLS and The Wanted were in second and third place with 30.85% and 15.69% of the vote respectively, while rival X Factor judge Cheryl Cole came in fourth place with 4.07%.