The 38-year-old talent show judge confirmed she will not take part in the auditions for this year's series due to her pregnancy with ex-rugby player Kris Smith - which will be in its latter stages when the first rounds of the show take place.
When asked about appearing on the show, Dannii said: "If they're auditioning in the hospital in Australia, yes, but otherwise, no!
"I will miss Cheryl, Louis and Simon, and not being there for the auditions, but I really need to be near my family in Australia at such an important time."
Dannii said she would like to take part in the show in some capacity but was unsure how it can work.
She added to website Digitalspy: "I don't know what is happening with 'X Factor'. I just adore it and I had such a fun time last year. I'd love to be part of it somehow even if I just pop back and visit."
The singer joined the show in 2007 and won the series in her first year with Scottish singer Leon Jackson.
Earlier this month Dannii admitted it would be tough to deal with all her personal and professional responsibilities.
She said: "I am definitely having my baby in Australia in July so it's going to be hard to juggle all of that."
Dannii has been dating Kris since she met him on holiday in Ibiza in 2008.