The 39-year-old, mother of two said that she was thrilled to become an "#AerieREAL Role Model" because of the messages the company sends to young women -- including her daughters Birdie, 10, and Cricket, 5.
"@Aerie is about empowering women and girls by showing images of real unretouched bodies," she wrote in the caption of a post announcing the news.
"I know for a fact I want my daughters to grow up in a world where they know and understand that true beauty comes from the inside out and true beauty doesn’t ever look just one way," she added.
"The more we can have images out in the world that reflect that to us, the more that will become our reality," she continued.
She also explained that she's struggled with body image insecurities for much of her life.
"I have always hated my stomach. Always," she wrote. "It’s the part of my body I have always been quick to say I would change if given the choice."
“”I know for a fact I want my daughters to grow up in a world where they know and understand that true beauty comes from the inside out and true beauty doesn’t ever look just one way.
Philipps said that idea was ingrained in her from an early age.
"When I was a preteen, there was an underwear ad that was everywhere (I even had it torn out and up on my wall) and the very famous model had what I thought was “the perfect stomach,”" she wrote.
"My stomach didn’t look like that. It never did and honestly, it never will. And so I deemed a part of my body a problem."
She later realized how much the perspective negatively influenced her well being.
"I wasted SO MUCH TIME thinking about my “terrible stomach” when my stomach is wonderful! Because it’s mine! And I’m not defined by my stomach or any other part of my body!" she wrote alongside the post.
Philipps also commented on her hope for more body diversity and unretouched photos in the media.
"I wish I had seen images of different women’s bodies in media when I was growing up," she wrote. "I wish I hadn’t been sold the lie that to achieve true happiness I needed a flat tummy and no hips so I could look like a model in an ad."
The company also tapped actress and body positive activist Jameela Jamil, blind YouTuber Molly Burke, para-snowboarder Brenna Huckaby and "Orange Is the New Black" star and LGBTQ advocate Samira Wiley for the campaign.
“These amazing Role Models embrace the Aerie lifestyle and were chosen for their influential voices, unique stories and commitment to nurturing an inclusive, empowering community for Aerie women everywhere,” Jennifer Foyle, Aerie Global Brand President, said in a press release.
The women will star in advertisements for the brand and share stories on body image and unretouching in the media, according to the release.