The couple - who welcomed their first child Camden into the world in August 2012 - tied the knot after purchasing a marriage licence at the Davidson County Clerk in Nashville, Tennessee on Friday).
Kristin tweeted: "Im officially Kristin Elizabeth Cutler!!!!! (sic)"
Kristin, 26, recently enjoyed a bridal shower at at The London Hotel in West Hollywood.
The bride to be was joined by a small group of her best girlfriends for the High Tea themed party which was sponsored by CIROC vodka.
While Kristin found fame on MTV reality TV shows 'Laguna Beach: The Real OC' and 'The Hills', the blonde beauty revealed she isn't inviting any of her former castmates to her wedding.
She said: "It's going to be family and really close friends. If the wedding were bigger, I would have loved to invite Audrina [Patridge], Stephanie [Pratt] and Heidi [Montag].
"It's going to be perfect. We're ready to be together for the rest of our lives."
Kristin added she is now fully prepared and ready for her big day.
She said: "Everything is planned and ready to go, but that's all I'm going to tell you."
- BANG! Showbiz