The 48-year-old told audiences live on air this morning that she would be leaving the popular breakfast program.
"I should probably start by saying I’m not pregnant – neither's Karl," she said.
"I’m going to be finishing up on the Today Show – I promised I wouldn’t get upset.
"I've given this a lot of consideration obviously but the time has come – I can’t look at you Lisa. I make this announcement with a very heavy heart because you are my family."
Richard Reid, Georgie Gardner, Karl Stefanovic, Lisa Wilkinson and Richard Wilkins in 2010.
Nine's Director of News and Current Affairs, Darren Wick, said Georgie would continue with her 6pm news duties with Peter Overton and the team.
He also said the popular presenter would take up the co-host chair on Mornings with David Campbell when Sonia Kruger is on Big Brother duties later in the year, and contribute to 60 Minutes.
"Georgie is a much valued member of the Nine News team and we welcome the opportunity to have her professional presence in a range of new roles across the network, including reporting on 60 Minutes," Wick said.