"I am thrilled to be expecting, and I can't wait to meet the new member of our family," she told The New York Post.
That family officially began in 2018 when the stars tied the knot in Scotland after dating on and off since 2012.
"The wedding was perfect," a source told E! News at the time. "Family and friends were elated for Rose and Kit. It was a day of love and celebration and you could see it on everyone's faces."
For "Game of Thrones" fans, the couple's real-life love story was a long time coming as they also portrayed Jon Snow and his lover Ygritte on the small screen. In a 2016 interview with Vogue Italia, Harington reminisced about falling in love with the actress while they were both shooting for the second season in Iceland.