This first image -- released to StyleList -- from the campaign shows the 16-year-old "Gossip Girl" star slightly more covered up than we're accustomed to seeing her of late (you'll recall she's been favoring briefs, garters, and Lucite stripper heels, complete with a tip slot, while performing with her punk band The Pretty Reckless).
The naughty-but-nice ads have Momsen baring very little skin, leaning against a chain-link fence in a gray sweater, black faux-fur vest, striped skirt, black tights, and rough-and-tumble leather combat boots.
The actress is accessorized with a stack of tough-girl chain and studded bangles, a silver double ring with a cross, black nail polish, and bright fuchsia lips.
It's somewhat ironic that Madonna would choose Momsen to front the line, considering that the wild child has often been compared to Madge's nemesis Courtney Love.
The women have had an ongoing rivalry over the years, with Love even tossing her compact at Madonna, who was in the middle of an interview at the 1995 MTV Video Music Awards.
Closer to the August 3 launch of the Material Girl collection, sold exclusively at Macy's, expect to see more images of Momsen, as well as a behind-the-scenes clip showing Momsen, Madonna, and her co-designer/daughter Lourdes collaborating on the shoot.
Want to see more Material Girl? Check out our sneak peek of the collection.