Sharing the news on Sunday, the beloved personality posted a photo of their newborn, revealing they named their bundle of joy "Jesse".
“Welcoming our beautiful baby boy Jesse Ryan to our family."
Adding next to his son's photo, "We love you so much. 29.07.2017 Sharing your birthday with your beautiful Mum. So proud of and in love with Kara."
Turns out the little cutie was born on a particularly important day- his mummy's birthday!
Kara also shared her happy news, writing, "Welcoming our beautiful Boy Jesse Ryan in to the world last night stealing our hearts and ...my birthday. We could not be happier."
The couple, who are already the proud parents to their little girl Remi, announced in February that his wife was expecting.
"Three of us, soon to be four... Excited. Happy. Blessed," the sports star wrote next to a stunning black and white snap of his wife's pregnant belly being touched by both Beau, Kara and their four-year-old.
The happy news comes after a tumultuous period for the pair, showing just how much they've moved on from Beau's 2015 cheating scandal.
In September, 2015, Kara was rocked by her husband's infidelity after it was revealed he had an affair with former Hi-5 singer Lauren Brant, whom he met while working on the stage production of Aladdin.
The mum-of-one sat down with Woman's Day in early 2016 to address the scandal.
"I was actually more worried for Beau, if I'm honest," Beau's high school sweetheart confessed.
"I'm probably emotionally stronger than Beau, and I could see how upset he was, so I was more concerned for him and our family," she explained.
Adding, "I'm probably emotionally stronger than Beau, and I could see how upset he was, so I was more concerned for him and our family."
In fact, the high school sweethearts are in the best place possible.
“We’re really happy at the moment, things are good, we’re really busy and it’s getting us all excited for the future,” Beau remarked earlier this year.
“Yeah, having another baby has made our relationship stronger and I’ve been home a lot with her.”