"Been hard to keep this a secret, but we couldn't be happier to add to our family", Aldean writes on Instagram, along with a photo of himself and Kerr, and their two dogs, sitting next to an open oven with a bun in it ("bun in the oven" - get it?).
The country star revealed his happy news in an Instagram post, featuring a picture of the couple wearing Baby Daddy and Baby Mama T-shirts.
While Aldean, 40, is already a father of two, this will be the first child for his 28-year-old wife of two years. The biggest rollercoaster we have ever been on, without a doubt!
She writes, "This was the hardest secret we've ever had to keep". All of the moments of heartache were followed by the biggest blessing in the entire world!
In March, Brittany spoke about her desire to have her own children, despite a close bond with her stepdaughters. The new addition joins Aldean's older daughters Keeley and Kendyl from a previous marriage.
Jason Aldean and his wife have clearly been planning their pregnancy announcement.
"We will never take one moment for granted", Kerr adds, "and can't wait to meet you, sweet baby!"