Mara revealed the news with a photo on Instagram that show her and the "Turn" actor kissing against a smoky background. The caption simply reads: "Nuptials." Bell shared the same photo on Twitter with the caption: "Me and Mrs. B."
Bell and Mara dated for two years after meeting on the set of "Fantastic Four," in which she played Sue Storm and he played The Thing. The movie bombed, but romance bloomed. They've been seen on various red carpets and high-profile events, including Fashion Week in Paris last month.
This is the first marriage for the former "House of Cards" actress and the second for Bell, who was previously wed to actress Evan Rachel Wood, with whom he has a child.