Amanda Holden will take Holly Willoughby's place on the This Morning sofa while she goes on maternity leave.
The Britain's Got Talent judge will join co-host Phillip Schofield on the show for four days a week from September, with Willoughby's third child due in October.
"I'm over the moon to get the chance to present one of my favourite shows on TV and I'm thrilled to be keeping Holly's seat on the sofa warm when she goes off on maternity leave," Holden said.
"I have always been a huge fan of This Morning and love presenting with Phillip so I really can't wait to get started."
ITV Daytime managing executive producer Emma Gormley said Holden's warmth and charisma would be a hit with viewers.
Stars and celebrities have been arriving on a red carpet with a difference at the Battersea Collars and Coats Gala Ball.
The guests at the charity event were greeted by some of the dogs from the animal shelter who will be benefiting from the money raised.
Judge Amanda Holden has compared tonight's Britain's Got Talent final to Christmas Day, while hosts Ant and Dec said they are looking forward to seeing all the acts: