Panettiere is one of the stars of the hit TV series "Heroes," as well as a recording artist and activist.
The list of past Candie's girls includes Fergie, Hilary Duff and members of Destiny's Child.
"I am excited to be working with Candie's," Panettiere said in a statement. "Their campaigns are fun and playful and always feature the hottest stars. I am honored to be the new Candie's 'girl' and I look forward to working with them on lots of exciting projects."
Panettiere is scheduled to make personal appearances on behalf of the brand of apparel and shoes, and to attend a launch party in Hollywood later this month.
"We are thrilled to have signed Hayden as our new Candie's girl. As one of Hollywood hottest stars, she personifies what we look for in a spokesperson. Hayden is not only talented and beautiful but also funny and irreverent," said Dari Marder, the chief marketing officer of Candie's.