The 33-year-old actor and his wife, singer Domino Kirke, are expecting their first child together after experiencing two miscarriages.
Kirke, 36, shared the news Monday on Instagram alongside a photo of her baby bump.
"On the road again... pregnancy after loss is whole other thing. After two miscarriages in a row we were ready to call it. I stopped trusting my body and started to accept the fact that I was done," the singer captioned the post.
"As a birth attendant, I've seen and heard it all. It takes everything I've got to detach lovingly from the losses I've been present for and be in my own experience," she said.
Kirke already has a son, Cassius, from a previous relationship. She said she's learned a lot since she was pregnant with Cassius at age 25.
"When I was pregnant at 25, I knew nothing. I had no community. I dove in blissfully unaware about birth and its mysteries," she said.
"Now, with 10 years worth of experience to pull from, I treasure my birth community and the knowledge I have. You're already teaching us how to stay in the day in a way we've never had to, little one. Thank you."
Badgley and Kirke married in New York in February 2017, and celebrated again with family and friends at a wedding that June.
Badgley praised Kirke as a "truly radiant soul" in a post on her birthday December.
"You encourage others to be honest, and brave, and gentle, and expansive," Badgley wrote. "Your great capacity for empathy is obvious, something anyone can get warm by like a glowing stove."
"Your desire to be of service to others is miraculous," he said. "You make others happy by you. For me, it is a joy to witness you when you are happy. For you, I always hope to be a source of joy. I'm really glad we're married."
Badgley is known for playing Dan Humphrey on Gossip Girl and Joe Goldberg on You, which started streaming a second season on Netflix in December. The series was renewed for Season 3 in January.
