Holly Willoughby
Chester is Willoughby's third child with husband Dan Baldwin after daughter Belle and son HarryGetty

Holly Willoughby has announced the birth of her third child.

The This Morning presenter and her husband Dan Baldwin welcomed a baby boy called Chester William on Monday evening.

The 33-year-old star, who is already mother to daughter Belle, two, and son Harry, four, gushed about her new addition on Twitter.

"I'm sooo happy to tell you all - we've just had a baby boy! Chester William Baldwin made a grand entrance at 8lbs 12. He's just perfect."

She was soon inundated with congratulatory messaged from fans and fellow celebs.

The proud mother later called in to This Morning to tell co-host Phillip Schofield and her stand-in Amanda Holden all about the birth.

"It was a very exciting evening, I started having contractions at about nine in the morning and they lasted all day and he arrived at about 7.20pm," she said.

"It was very different from my other two - I had a water birth and that was amazing, and he was a really big boy!

"He's so delicious, I just can't stop looking at him, and he's just perfect."

Willoughby hosted her final show with Schofield earlier this month before going on maternity leave.

It is believed that Holden may co-host the show for up to a year.