The presenter posted a picture of herself with her newborn in a sling on her Instagram account on Saturday morning.
Laura wrote: “Thanks for all the kind messages at this time. We are in love x.”
The couple have not yet shared the name of their new arrival.
Laura previously revealed she and Love Island narrator Iain were expecting a baby girl in her new book No One Can Change Your Life Except For You.
She wrote: “As I finish this book, it doesn’t end at chapter nine, there’s a new chapter coming into my life – in the form of a baby girl currently growing inside me and that scares the s*** out of me.
“I once swallowed a bug and freaked out there was a live bug inside me. A live human is a whole new level of freaking out but I am excited because there’s a lot of good in the world, there’s a lot of potential.”
Laura added: “I want to bring up my child knowing that she has her own story to write. She will be supported and loved. But she is the heroine of her own life, no-one else.”
Laura and Iain announced they were expecting their first child in December with another sweet Instagram post.
It followed reports that they had privately tied the knot earlier in the year, something the pair later confirmed on social media.
The pair met at a TV awards ceremony in 2016 but did not get together until later.
Laura worked alongside Iain on the most recent series of Love Island in January 2020, after succeeding the late Caroline Flack as the ITV2 reality show’s presenter.
They are both set to resume their roles on the upcoming series, scheduled to take place in the summer.