“Lee and I, we decided to separate,” the 43-year-old said on air.
“It’s not a decision we took lightly at all… We have been so lucky that our separation has been extremely amicable.”
The media personality said the the pair remain good friends, and that the former couple still talk on the phone everyday and hang out as a family for the sake of their seven-year-old daughter Kitty.
“I know everyone says that, but we actually have remained really good friends throughout all this,” she said.
Her co-host, Kyle Sandilands, was deeply affected by the announcement.
“I cried yesterday, didn’t I? I didn’t mean to upset you,” he said.
Jackie O first announced her separation in an article that was published in the Daily Telegraph on Friday morning.
“After 18 years together, we have made the decision to separate,” she said.
“We do so amicably, sharing many incredible memories and remaining best friends.
“Our focus for this next chapter is, of course, our wonderful daughter and continuing to provide her love and happiness, together.”
Jackie and Lee, a professional photographer, met when the British national was backpacking around Australia. The pair were married three years later in 2003.