Credit: Gregg DeGuire/WireImage

Scarlett Johansson quickly whipped her body back into shape after giving birth to her first daughter last September and hasn't been shy about showing off her hard work. At the 2015 MTV Movie Awards she wore a long-sleeve jumpsuit (and had envy-inducing pixie), but for Monday's Avengers: Age of Ultron premiere, the star went for a skin-flashing black dress. This wasn't your typical LBD: The sleeveless number included a seductive hem in the front that allowed the star's toned arms and legs to take center stage. Her Jerome C. Rousseau heels ($695; with gold metal details added a touch of sparkle to the ensemble.

The hardworking actress hasn't slowed down since giving birth. She's even confirmed to host her fourth episode of Saturday Night Live, which will air the day after her latest film hits theaters, on May 2, 2015. One thing is certain: This hot mama knows how to work it.