Mara's rep confirmed their engagement to E! News after the actress was spotted wearing a ring in New York City. She also sported the ring in a picture she posted on Twitter.
The couple met when they made the "Fantastic Four" in 2014. She played Sue Storm, he played the Thing. Their relationship became public a year later at the Met Gala and since then, they've appeared together at many events and red carpets.
"Fantastic Four" bombed at the box office, but it seems like there was at least a bit of silvering lining.
This is the first marriage for Mara, 33. Bell, 30, was previously married to Evan Rachel Wood, with whom he has a son.Want more stuff like this? Like us on Facebook.