The couple matched in all black, with Downey Jr., 51, donning a suit with satin accents and his wife wearing a dress, which featured a mesh cutout and hit right below the knee.
Downey stars in the film alongside Chris Evans, Scarlett Johansson and Jeremy Renner, as Captain America (Evans) and Iron Man (Downey Jr.) spar, leaving other members of the avengers to pick a side.
"Natasha [aka Black Widow] is a bit torn between either side," Johansson said about her role in the film. "With Cap they really have a relationship where she wants to reason with him. But she sees Tony as a path of least resistance."
Fans have a little less than a month to see how it all plays out as Captain America: Civil War hits theaters on May 6.