The 21-year-old wore a vintage silk gown for the world premiere of her new film, The Black Dahlia, in Venice.
Her look was topped off with scarlet lipstick and a diamond butterfly pinned in her hair.
Johansson was joined on the red carpet by co-stars Josh Hartnett and Aaron Echart.
The ’40s-inspired look echoes the costumes Johansson wears in the film.
The Black Dahlia is based on James Ellroy’s novel about the real-life murder of wannabe actress Elizabeth Short, whose mutilated body was found dumped on a wasteground in Los Angeles in 1947. The killer has never been found.
Hartnett and Eckhart play cops investigating the murder while Johansson is Kay Lake, the femme fatale caught between them.
Johansson said she jumped at the chance to take the role.
“What attracted me most to the character was her will to survive. She’s a survivor, she’s had this crazy life and she will do anything she can to get away from it,” she said on the red carpet.
The star of Lost In Translation and Match Point shows off her famous curves in the film.
One critic told Johansson she oozed so much sex appeal on screen that audiences might be distracted from the plot.
“I never think about these things,” the actress said. “Of course, it’s nice to be considered sexy, as a young woman in my prime. But I try not to let it be distracting from a scene.”
This is the second Ellroy novel to make it to the big screen, after the acclaimed LA Confidential.