The baby boy, who Egan and Albert have named Zeke, was born at 7.49am on Thursday 21 May, weighing 7lb 13 oz.
The couple already have a three-year-old son, called Koa, who will be settling into his role as a big brother.
Egan shared the news on Facebook and also payed a tribute to his wife's late grandmother, who would've shared the same birthday with Keke.
The 35-year-old singer added: "We are all so happy and so in love with him x".
Albert is yet to share any snaps of her newborn, but we bet he's a cutie.
The 31-year-old actress married Westlife-star and "King of the Jungle" Egan in 2009, and now they have a gorgeous little family.
Albert shared this photo of Koa, earlier this month with curly locks and some shades.
"He is literally like a mini Kian!" wrote one fan.
... We bet he is one very happy big brother.
Congrats to the couple - it seems like there has been a lot of baby news recently!