The legendary designer, who dressed Princess Diana and shaped Irish fashion for decades, was a mainstay at London Fashion Week since 1984.
Irish-American fashion legend Paul Costelloe, best known as the personal designer of the late Princess Diana, has passed away at the age of 80, his family confirmed on Saturday, November 22, 2025.
“We are deeply saddened to announce the passing of Paul Costelloe following a short illness,” the family said, adding he died peacefully in London, surrounded by his wife and seven children.
Costelloe was a towering figure in Irish fashion, consistently showcasing his work on the opening day of London Fashion Week since the show’s inception in 1984.
Born in Dublin in 1945, he trained as a design assistant at top French fashion houses in Paris before joining Marks & Spencer in Milan. In 1983, he became Princess Diana’s personal stylist, a role he held until her untimely death in 1997.
Reflecting on working with the late princess, Costelloe told RTE earlier this year, “She was very human, she didn’t act like a princess… She made a very good cup of tea and some scones.”
Renowned for his romantic and tailored designs, Costelloe fused classic styles with contemporary flair, often incorporating tweeds, florals, and bold pops of colour into his collections.
Even in recent years, he remained active, presenting his 1960s-inspired Spring/Summer collection, “We Stroll Down Rodeo Drive”, at London Fashion Week. His family business also continues under his son William, who serves as design director.
Reflecting on his legacy, Costelloe told Vogue in 2024, “My ambition is to step back from fashion eventually… To hire an old car and drive around France and paint.”