The ex-Strictly Come Dancing professionals announced the birth of their daughter on Twitter on Saturday night.
It is the first married couple for the couple, who had undergone a “tough process” of IVF.
Ola shared a picture of her baby’s hand, writing: “She’s here and she is perfect. #Mummy.”
Husband James showed off the newborn’s feet and wrote: “I’m the happiest man in the world #daddy.”
Ola and James were trying for a baby for nearly three years before undergoing fertility treatment.
James previously described Ola getting pregnant as the couple’s “biggest achievement”.
He told Hello magazine: “We’ve been with each other for 20 years, married for 16, travelled the world, achieved amazing things in our careers: trophies, accolades, Ola won Strictly Come Dancing, I won Dancing On Ice. But finding out that we are pregnant is no doubt our biggest achievement ever.
“This is probably the most special and exciting thing that has ever happened to us.”
Ola joked: “When we had the scan it was funny because the baby was dancing. I’m not sure if it was a cha-cha or a jive, but it was definitely dancing.”