As any parent knows, welcoming new life into the world is an incredible experience.
On Monday night, the beaming Today star uploaded the first photo of his latest addition to his Insgragram page, alongside an emotional caption wishing Harper a happy life.
"Harper May. May your life be filled with as much love as I feel. My children. My family. My wife. My life," the 45-year-old penned, alongside a photo of his newborn daughter resting peacefully on his chest.
The touching post was inundated with well-wishes from famous faces.
"Beautiful," Ninja Warrior star Ben Fordham wrote.
"Congratulations," Love Island host Sophie Monk added.
"Brilliant! Welcome to the world. Nice job Mum & Dad. x," Osher Gunsberg said.
"Bubba!!!" Nine newsreader Deb Knight mused.
According to the Sydney Morning Herald, Harper was born via a planned cesarean section.
"Harper and Jasmine are doing well and dad had a great night's sleep. I am in awe. Harper is absolutely perfect," Karl said in a statement announcing the happy news over the weekend.
Harper is Karl's fourth child - he shares his three eldest children Jackson, 20, Ava, 14 and River, 12, with his ex-wife Cassandra Thorburn.
Last week, Karl admitted having a baby with Jasmine was on the cards as soon as they fell in love, despite undergoing a vasectomy, a procedure he later had reversed.
"We discussed it very early on in our relationship and I was very excited about the prospect of having a baby," he told the Daily Mail Australia.
"We [he and Jasmine] do have a very loving relationship and to have a baby as an expression of that love is incredible. It's never an easy thing and I think that kids are a miracle and we just can't wait to meet this little girl. Just to shower her with all the love that we have," he said.
Harper will be in great company as she joins cousin Oscar Stefanovic, the first child of Karl's brother Peter Stefanovic and wife Sylvia Jeffreys who was born in February.