The Project host, who was born in Adelaide, South Australia, also revealed the gorgeous bub's name as 'Adelaide.'
The couple announced the news on Instagram along with an adorable photo of the newborn.
“Welcome to the world little ADELAIDE (or Addie as your siblings have already started calling you) We are absolutely besotted with you,” the post read.
The 38-year-old shares three-year-old daughter Evie with partner Chris. Bickmore also had 11-year-old son Oliver with husband Greg Lange, who tragically died from brain cancer in 2010.
The TV star recently told Stellar magazine that she is both exciting and nervous about becoming a mum of three.
“I am equal parts terrified and excited,” she said. “I have been taking advice from other parents on managing three children because I honestly have no idea what to expect. I don’t have a lot of friends with three kids, so it’s all a bit of a mystery to me.”