The bride wore a white silk jumpsuit during her civil ceremony, which no royal has done before.
For her cathedral wedding, Marie wore a gown designed by her new sister-in-law Pauline Ducruet, who graduated from Parsons School of Design in 2017.
The guest list comprised of close family and friends, including Prince Albert II, Princess Charlene, Princess Stephanie, Pauline Ducruet and Camille Gottlieb.
Louis' father Daniel Ducruet was also in attendance, along with several of the groom's half-siblings.
According to People, it was "love at first sight" for Marie and Louis.
The couple has been together since 2011, after meeting at a Cannes nightclub and realising they attended the same business college.
Leading up to their wedding, the usually private couple shared their excitement on social media.
“You are my heaven on earth,” Louis wrote in the caption of a photo with Marie.
Marie posted a photo of Louis and their rescue dog Pancake, captioning it, “My happiness.”
