Princess Kate's 'inappropriate' outfit Prince William warned her against wearing


Royal advisors recalled the Princess of Wales' fashion mishap behind closed doors, which her husband thought went against the grain of "dressing carefully"


Prince William and Kate Middleton looking concerned© Getty Images
Nichola Murphy
Nichola MurphyLifestyle Editor
Updated: July 9, 2026
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The Princess of Wales' fashion sense is a far cry from "inappropriate", but that is exactly how her husband Prince William categorised one of her outfits in the past.

Shortly after marrying into the royal family in 2011, Kate cemented her place as a global style icon with her mass sell-outs called 'the Kate effect.' Today, she has mastered mindful dressing, from paying tribute to host countries during royal tours to championing British designers with her day-to-day outings.

But this sartorial prowess took years to fine-tune, according to a confession from one of William's advisers. They recalled to The Times that the couple shared a laugh about an outfit that was considered going against the grain of "dressing carefully" – reading between the lines, we're assuming high necklines, low hemlines and generally modest and elegant style rules were not abided by.

"Before Kate realised that as a senior royal you have to dress carefully, having taken advice, she once bought an outfit that William considered inappropriate," the advisor said. 

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"He told Kate she looked as if she’d just run through a charity shop covered in superglue. Everyone thought this was very funny, including, to her credit, Kate."

Prince William and Catherine in blue© Getty
Prince William's wife is known for her elegant outfits today

They did not reveal exactly which outfit was in question, but it's likely that Kate heeded the warning and didn't wear it out in public. It could have been amid her gradual fashion transformation from pre-royal life attending parties in London with her friends to joining William on senior royal outings.

Case in point, she famously caught Prince William's eye after wearing a sheer Charlotte Todd skirt as a dress at the University of St Andrews fashion show in 2002. Fast-forward to 2008 and Kate once again showcased her daring fashion sense in a green sequin halterneck top, neon-yellow hot pants, pink leg warmers and knee-high heeled boots for a charity roller disco.

Kate Middleton in a sheer dress and bandeau bikini© Malcolm Clarke/Daily Mail/Shutterstock
The then-university student's iconic sheer dress caught the attention of a young Prince William

Just two years later, Kate was the picture of poise at her engagement photocall with the Prince of Wales in a blue wrap dress by Issa – the official start of her foray into royal life and the accompanying style rules.

Kate attended a roller disco in 2008 in yellow hotpants© Max Mumby/Indigo
Kate attended a roller disco in 2008 in yellow hotpants

Since then, she has been known to rely on luxury labels such as Alexander McQueen and Jenny Packham for timeless pieces.

The Times also reported that Kate seamlessly settled into royal life with the help of staff thanks to her ability to "absorb" the atmosphere and expectations.

 Prince William and Kate Middleton pose for engagement photographs in the State Apartments of St James Palace on November 16, 2010 in London, England. © Getty
Kate looked elegant in an Issa dress for her engagement photocall with Prince William in 2010

"Kate is someone who slowly and carefully absorbs the atmosphere of a place, the relationship between people and the rules. She doesn’t jump in straight away and try to change everything to suit her way of thinking. 

"She bides her time and is very intelligent and intuitive about other people, what they do and how they behave. She was also coached – not just by William, who wanted Kate to avoid the problems his mother had encountered, but also by the staff."

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