They are well known for wearing high street brands and not being afraid of recycling items of clothing.
Not only they tend to go for similar looks and outfits but have also opted for the same hairstyle and makeup many times, becoming admired for their similar style sense.
Both look flawless in all their appearances and tend to impress fans with their impeccable fashion choices.
Between Queen Letizia’s elegant looks and Kate’s effortlessly chic style, it can be hard to pick a favourite. They are both considered real fashionistas.
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Fashion expert and director of Luxury Legs, Stephen Sheldon, said: “They’ve both certainly featured alongside each other in their fair share of fashion round-ups.
“They have the same understanding of understated elegance.”
The expert described Queen Letizia’s style as “definitely one of formality and statement.”
He explained that both royals definitely share a similar style and that, just like Kate, “Queen Letizia will dress for the occasion.”
He said: “Just a few days ago she sported statement sleeves in a summery informal look while visiting the student residence hub in Madrid.”
The royals also share the same taste when it comes to fashion brands, which include Zara, Massimo Dutti, Mango or Carolina Herrera.
The pair have worn almost identical outfits several times, and they usually opt for tailored pieces and floral dresses in the summer months.
However, he said there is one more European royal who usually gets compared to the British one in terms of looks.
“I’d say there are three European royals who often get compared when we’re talking fashion.
“Queen Letizia and the Duchess of Cambridge certainly share many similarities in style but Princess Sofia of Sweden also channels this same thread of statement simplicity,” he said.
“All three royals are experts in applying fashion advice from a variety of tastemakers from the 21st and 20th centuries.
“They know less is often more, but aren’t afraid to add a touch of extravagance when the occasion calls for it,” he explained.
But who wins the battle?
For the fashion expert, it is very clear: “I would have to say Kate Middleton!
“She champions British designers and our high street favourites, so has done a lot to boost the British fashion industry.
“She is the master of understated elegance.”