Rihanna makes her biggest foray into fashion yet as the new body for Emporio Armani’s underwear. She follows the racy Megan Fox, who was paired with soccer hottie Cristiano Ronaldo last year.

The Armani ads for the product line, at least in the past, focused on physical fitness. Before Fox and Ronaldo, the brand was represented by soccer star David Beckham and his wife Victoria.

Rihanna is sultry, but she’s also more solidly built with, let’s face it, a bootie that Kim Kardashian would die for.

Rihanna is set to appear in the autumn-winter 2012 underwear ads.

Check out Rihanna’s photos; click to enlarge:

She could be joined by Spanish tennis star Rafael Nadal.

He has also been signed by the label, but whether they will be pair together remains to be seen.

The Beckhams were photographed together, but Fox and Ronaldo were not.

The 23-year-old’s fashion credentials continue to grow.

Rihanna has been the face of Cover Girl cosmetics since 2007, and she recently signed a deal with Nivea.

Rihanna also fronts the Vita Coco brand, coconut water popular with celebrities.

Fox replaced Victoria Beckham in October as the new face of Armani’s Women’s Underwear for Spring/Summer 2010 collection. The move comes as Armani moves to freshen the brand with younger models.

Top fashion photographers Mert Alas and Marcus Piggott, who also photographed Fox and Beckham, shot the campaign on location in New York and the ads will launch in September worldwide.

The singer is obviously excited about the deal.

“U would NEVER guess what I’m doing right now!!” she Tweeted. “Hint Hint #Armani.”