Zara, the eldest granddaughter of Britain's Queen Elizabeth, beat her cousin Princess Beatrice and supermodel Naomi Campbell to the top of the list, which is compiled by Luton's millinery and hat-making industry.
Prince Harry appeared at number five on the men's list, which was topped by actor Brad Pitt.
Philip Wright, of Luton milliner Walter Wright Ltd, said: "Zara has opted for the more masculine but highly-fashionable trilby and fedora hat styles, together with some of the neat, chic, 1920s-inspired designs. But she's also gone for some fairly extravagant styles which are both fashionable and fun."
Although Prince Harry also featured in last year's list, Wright suggested he has a long way to go before he catches up with his ultra-stylish cousin.
He said: "We have the royal princesses and Kate Middleton waiting to take on Princess Diana's fashion crown but we are still waiting for a Royal male to show a positive style lead in all aspects of the male wardrobe."
TAGS: Europe Zara Phillips