The former Olsen Twin child star tied the knot with French banker Olivier Sarkozy in New York on Friday night, according to New York Post's Page Six.
A source says the newlyweds wanted the ceremony to remain private so asked all guests to hand over their mobile phones ahead of the nuptials. It's also claimed they had 'bowls of cigarettes' around the private residence for guests.
No further details have been released.
Mary-Kate, 29, became engaged to 46-year-old Olivier last year following a two-year relationship. He's the brother of former French president Nicolas Sarkozy.
In an interview with the Wall Street Journal she said she didn't care what critics of their age gap may think. "Everyone has an opinion. I find it's better to focus on what's in front of you and to keep putting one foot in front of the other."
Olivier has two children with his ex-wife.
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!