In 2014, Badgley found lasting love with musician Domino Kirke. The pair were spotted out and about in NYC that summer, and according to People, they bonded over their shared Baha'i faith.
In 2019, Badgley paid tribute to his wife with a sweet Instagram post. "Happy birthday, Dom," he wrote in the caption. "A super-brief review of your invisible qualities: A truly radiant soul, you seem to spark alight almost everyone you meet, like a 99% success rate. It's really impressive, and quite mysterious. You encourage others to be honest, and brave, and gentle, and expansive. 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. It is in your DNA."
They first tied the knot at an NYC courthouse in February 2017 and followed that with a larger wedding that June. Kirke has a son named Cassius from a previous relationship, and in February 2020, she and Badgley announced they were expecting their first child together, a baby boy, whom they welcomed that September.