The 38-year-old Australian singer finally confirmed weeks of speculation by revealing on micro-blogging website twitter that she and boyfriend Kris Smith, 31, are expecting their first child together.
She wrote: "Woo hoo I'm gonna be a mummy! :-) (sic)."
The star – who is currently holidaying in Melbourne with Kris – is believed to be due to give birth in July and is "very excited" about the new arrival.
Her spokesperson said: "Dannii and Kris are very excited and can't wait to start their family in 2010. Rumours and stories surfaced across the weekend about Dannii being pregnant and having already had her 12 week scan. These stories were incorrect. Dannii had her 12 week scan this week and was given the results today with the all clear to make an announcement."
Dannii – who has been dating Kris since September 2008 – has previously revealed her relationship with the rugby player made her rethink her attitude to motherhood.
She said: "I've never been maternal. I almost thought I was going to escape it, and now I'm in a relationship that is just so right, maybe I have to think about it."