The presenter will front the Saturday night Strictly Come Dancing rival, which sees celebrities team up with their real-life partners in an attempt to master a different genre of dance each week.
McCall said that the show's in-depth look at the contestants' relationships will set it apart from other dance programmes.
She said: "I am so excited to be a part of Stepping Out. It is going to be full of joy and laughter.
"One of the main reasons why I am really looking forward to the show is that it is much more than a dance show. It is about the couples and how they relate to each other, and I really like that aspect of it. It makes it very different to other dance programmes."
The presenter - who also hosts Got to Dance and The Million Pound Drop - admitted to being both nervous and excited about fronting the series.
She said: "I am really excited about this show. Yes, I am nervous, as I always am with any new series, but I think it is going to be a lot of fun."
Celebrities competing in the show include former Westlife star Brian McFadden and wife Vogue Williams, Loose Women's Denise Welch and her husband Lincoln Townley, and JLS singer Oritsé Williams and his girlfriend AJ Azari.
Stepping Out launches on August 31 on ITV.