The singer and his wife Danielle announced the big baby news on social media Monday.
"Prepping for baby number two!" the former "Celebrity Apprentice" contestant wrote on Instagram, alongside a photo of him in bed reading "What to Expect When You're Expecting Again" next to his pregnant wife.
The couple, who recently celebrated their sixth wedding anniversary, are already parents to 2-year-old daughter Alena Rose.
Turns out, Alena is just as excited as her parents about the baby news.
Someone is happy ?? pic.twitter.com/XEZvE7cLds— Danielle Jonas (@daniellejonas) April 26, 2016
Someone is happy ?? pic.twitter.com/XEZvE7cLds