Mason was born in Linköping, Sweden, and grew up in the neighborhood of Ryd, Linköping. She moved to the United States with her family at the age of 12. She was raised around the Chicago area. She currently lives in Los Angeles, California with her husband David Denman, whom she married in August 2014. The couple welcomed their first child on 10 January 2018, a son named Caius Kane Denman.