Kate Middleton wears sexy thigh-split white dress for London event with Prince William
She added extra glamour to her outfit with a pair of sparkling £450 Jimmy Choo Vamp sandals, a diamanté clutch and chandelier-style earrings.
And the Duchess of Cambridge, whose high-necked frock is believed to be a 2009 design by Roland Mouret, vamped up her look with red toenails.
Kate, 30, and Wills, 29, were attending a 'secret' meeting of the prestigious Thirty Club at Claridge's hotel.
Wills looked dapper as ever and gave a speech to members, who are some of the most powerful men and women in advertising and the media.
'The Duke has been invited for around 9 years now and thought it was right to accept the invitation this year because of the Queen's Diamond Jubilee,' says a St James's Palace spokesman.
'It also seemed rather apt as it his 30th birthday next month.'