The This Morning presenter oozed sex appeal as she posed in a white lace bra for a Pretty Polly shoot back in 1999.
Holly gazed seductively at the camera, with her showing off her toned stomach and a hint of cleavage.
She highlighted her natural beauty with a slick of pink lipgloss and she wore her then-brunette locks in loose curls cascading down her back.
The latest saucy shot of Holly – who shared an adorable photograph on Instagram this morning of her celebrating her birthday with her three children – comes after a seriously sexy clip of her squeezing her ample bust while posing for the lingerie firm resurfaced.
Holly Willoughby stripped down to a white bra for a Pretty Polly shoot back in 1999
The footage showed Holly writhing around in white lacy undergarments, with her and her fellow lingerie models acting out "the story of the bra" for viewers.
Holly Willoughby could even be heard screaming: "I'm a sex goddess," before adding: "Don't squeeze them, lift them."
The star looked a far cry from how fans know her today, with her wearing her slightly darker hair in tight ringlets around her shoulders.
The voiceover at the end of the racy film then explained: "Pretty Polly bras, it's the way they make you feel."
Holly also starred in a racy Pretty Polly TV advert back in the nineties
Holly Willoughby in pictures
Thu, January 26, 2017
This Morning host Holly Willoughby in pictures
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Holly Willoughby wows in plunging pink gown at the National Television Awards
Holly did an interview a few years after the advert aired, with her insisting that she would "never say never" when it comes to modelling more seriously sexy lingerie sets.
The blonde explained: "When I started as a model I did a lot of lingerie work but it was for Pretty Polly, which is a very safe brand.
"It’s been less than a year since I had my second baby so I would need some time to get in shape, but I would consider it.
"Having the time to do all these things is the real problem," she added to the Daily Mail.