Walking the red carpet at the Captain America: The Winter Soldier premiere Thursday night in Hollywood, the 29-year-old actress, who is engaged to French journalist Romain Dauriac, diverted attention from her barely-there baby bump with a sexy, low-cut lace ensemble.
Looking sunny and smiley, Johansson stopped to sign autographs for fans before heading into the screening. Superhero costars Chris Evans, Emily VanCamp, Cobie Smulders and Samuel L. Jackson also attended.
In early March, PEOPLE confirmed that Johansson, who plays Avengers member Black Widow in the flick, is expecting her first child with Dauriac, 31. Though she has yet to comment on the news, the actress said she's thrilled about her engagement.
"I'm very happy," Johansson told PEOPLE in January. "He's my buddy."
With reporting by SCOTT HUVER