Holly has stripped off for a good cause though - by calling on the public to taking showers in just three minutes in a bid to save water.
Squeaky clean: Holly Willoughby lathers up in the shower to support World Water Day
The Dancing On Ice host said the idea that rainy Britain had a plentiful water supply was false because the population is so high.
And with the UN World Day for Water coming up on Saturday, 27-year-old Holly said 90 billion litres of precious water could be saved if everyone trimmed shower times.
She said: "Because we're such a small country and there are so many people in the country, the amount of water per head is so minimal - we've got less water per head in the south-east of England than they have in Sudan."
The former underwear model, whose plunging necklines on Dancing On Ice have raised more than the odd eyebrow, said she had managed to wash her hair in three minutes.
She went on: "The average is about seven minutes for men and about 7.2 minutes for a woman so it's not that much difference. Every minute you spend in the shower you use nine litres of water.
"Aim for the optimum three-minute shower then you're going to save a lot of water.
Wet look: The TV presenter has called on the public to reduce their shower time to just three minutes
"If everybody did that in a day you would save... enough to fill 9,000 Olympic-sized swimming pools in one day."
Holly also said the latest Dancing On Ice series had "some of the best celebrities we've ever had".
She added: "The final I think is probably one of the most exciting pieces of TV I've ever seen in my life. Suzanne Shaw was an absolute deserving winner - she won on the night so she was fantastic."
• Holly Willoughby is the spokesperson for the Ariel 3 Minute Shower Challenge for World Water Day
Elegance: Presenter Holly at the Royal Television Society Programme Awards in London on Wednesday night