They confirmed a month ago that they are expecting their first child together.
And on Tuesday night, Kate Mara showed off her growing baby bump as she accompanied husband Jamie Bell to a special Hollywood screening for Teen Spirit.
The actress, 36, was the epitome of maternity chic in a short-sleeved black mini dress with silver pattern trim.
Mara went bare-legged in a pair of black sandal heels and carried a small black purse.
Bell, 33, served as an executive producer on Teen Spirit which stars Elle Fanning and is directed by Max Minghella.
The actor kept his look casual choosing a white t-shirt with black trousers and a silky black bomber jacket.
While the new arrival will be the first for Mara, it will be Bell’s second child, as he already shares a five-year-old son with his former wife Evan Rachel Wood.
Mara and Bell met on the set of the Fantastic Four movie in 2015.
They confirmed their engagement in January 2017 and tied the knot just a few months later in July.