What's interesting is that the couple never even announced that they were expecting!
The comedian's rep confirmed the news.
The funny man and his wife, a pianist, married in September 2013 in Big Sur, California, after five years of dating. He has previously said that he would be totally open to having kids.
"I love babies," he said last year, according to People magazine. "I would love a baby someday."
He was asked if he felt any pressure to have a child since many of his friends were starting families.
"No," he said, "I don't think a baby is something that you should do because other people are doing it."
In December of 2015, Joanna told Larry King that they were thinking about children. "Little harpist Samberg, thank you for putting that image in my head," she said.
In the same interview, she gushed about her husband. "He's my favorite person in the world. He's the person I would most want to hang out with at any given moment. He's probably the biggest superfan of my music."