Karlie Kloss and Christian Siriano to replace Heidi Klum and Tim Gunn on 'Project Runway'

Karlie Kloss is one busy model!

The fashion star is replacing Heidi Klum on "Project Runway" as host and executive producer, while designer Christian Siriano, a "PR" alum, will take over Tim Gunn's role as mentor.

Elle editor-in-chief Nina Garcia will return as a judge along with a pair of newcomers: designer Brandon Maxwell and former Teen Vogue editor-in-chief Elaine Welterorth.

The news comes following the exit of Klum, Gunn and designer Zac Posen, which was announced in September. Klum and Gunn will be embarking on a new fashion reality show with Amazon.

“After 16 incredible seasons, I am saying 'Auf Wiedersehen' to 'Project Runway,' a show that I was honored to host and help create,” Klum said in a statement at the time.

“I am incredibly proud of the show, and it will always have a special place in my heart. I am so appreciative of the dedicated fans, and most of all, I am grateful that we could shine a light on creativity and help launch so many talented designers' careers. I’m most excited that my journey with my dear friend and colleague, Tim Gunn, is far from over. We will be partnering with Amazon for a new show, and we’re excited for everyone to see what we’re designing next!”

During New York Fashion Week, ET's Marisa Runyon spoke with Siriano, who responded joyously to the news of Klum and Gunn's next endeavor. "So exciting! I know. Congratulations to them. It's awesome and I mean, they're amazing. They're a powerhouse, so it'll be, I'm sure, a great show," he said.

Heidi Klum and Tim Gunn previously announced they were leaving “Project Runway” to join Amazon for a new series.

Heidi Klum and Tim Gunn previously announced they were leaving “Project Runway” to join Amazon for a new series. (Getty Images)

Siriano has become a go-to designer for the stars, dressing an array of Hollywood celebs including Leslie Jones, Ashley Graham, Sarah Hyland and Danielle Brooks.

Kloss, who recently became engaged to Joshua Kushner, rose to prominence in 2008 as she walked in almost every major runway show. The 26-year-old supermodel has appeared in numerous campaigns for Versace, Louis Vuitton, Givenchy and Marc Jacobs, just to new a few, in addition to founding Kode with Klossy.

"As someone who grew up watching 'Project Runway,' I could not be more excited to host and produce a series that provides a platform to aspiring American designers as they pursue their creative and entrepreneurial dreams,” Kloss said in a statement.

“I am equally as thrilled to work alongside an incredibly talented group of fashion innovators -- Brandon Maxwell, Elaine Welteroth, Nina Garcia and Christian Siriano — to inspire, support and help guide these designers as they realize their visions and build everlasting brands and businesses.”

"Project Runway returns" to its original network Bravo after moving to Lifetime in 2008. Season 17 will premiere in 2019.