The Fantastic Four's Invisible Woman and The Thing are getting married!
The news comes soon after Mara was spotted walking in New York City wearing a ring with a large stone on her ring finger.
She also wore a sparkling ring in a photo posted on Twitter this past weekend.
The 33-year-old actress and Bell, 30, had sparked engagement rumors last year after the actress was seen wearing a ring on her ring finger. When asked then if they were engaged, the British actor told E! News, "No," while the actress chucked at the question.
Mara and Bell met on the set of Fantastic Four in 2014. They first fueled dating rumors at the Met Gala in May 2015, holding hands as they made their way into a private after-party. That September, they were spotted looking cozy on a beach in Malibu.
A month later, they were seen kissing on a street corner in New York City.
Mara and Bell have since attended many celebrity events together, including the H&M Womenswear Fall/Winter 2016/2017 show at Paris Fashion Week, the 2016 Met Gala, and most recently, the Hollywood premiere of the actress' latest movie, Man Down, in November.
This will mark the first marriage for Mara. Bell and Westworld's Evan Rachel Wood split in 2014 after 19 months of marriage and almost a year after welcoming a son.