The pair confirmed the good news to People on Thursday with a statement, saying, "The Kelley clan is thrilled to announce that we are expecting a third addition to our family."
The new baby, who is reportedly due in January, will be a little sibling to Heigl and Kelley's two adopted children, Naleigh, 7, and Adelaide, 4.
"Naleigh and Adelaide could not be more excited to welcome their new sibling into the fold and Josh and I are overflowing with joy and gratitude,” Heigl said.
“This is an incredibly exciting time for us filled with hope, anticipation, and hormones. Well, only I’m filled with hormones, but everyone in the family gets to enjoy them,” Heigl joked in the statement. “We couldn’t be more excited to be able to finally share this news with our fans and are looking forward to continuing to share the journey with you all. xoxo, Katie and Josh.”
Heigl and Kelley met in 2005 when the former "Grey's Anatomy" star appeared in one of Kelley's music videos. They wed in the winter of 2007 in a private reception in Park City, Utah.
In 2009, the couple adopted their first child, Naleigh, from South Korea, and in 2012, they welcomed Adelaide, who was adopted domestically, to their family.