Swanson was born in Mission Viejo, California, the daughter of physical education teachers Rosemary and Robert Swanson. Swanson and her Skating with Celebrities partner, Lloyd Eisler, began dating in December 2005. The couple welcomed their first child together on February 16, 2007. The pair were together in Kingston, Ontario in February 2006 to promote and host the annual FebFest event.

Kristy was arrested on June 16, 2007 for an alleged assault on her companion's ex-wife. Her lawyer, Constance Baran-Gerez, arranged for charges to be withdrawn on October 31, 2007.

Swanson has dated actors Alan Thicke and David Spade in the past.