Paul Costelloe, Princess Diana’s personal designer, passed away at the age of 80 on Nov 21, 2025. The Irish fashion designer held this role for more than a decade, dressing the Princess until her sudden death in 1997. 

Costelloe moved constantly in his early life: Dublin for the Grafton Academy of Fashion Design, then Paris for the prestigious Chambre Syndicale de la Haute Couture and Jacques Esterel, who appointed him Design Assistant. A job at Marks & Spencer brought him to Milan before he became a designer at luxury department store La Rinascente. Crossing continents, he became a designer to Anne Fogarty in New York. In 1979, Costello established his own label, Paul Costelloe Collections. 4 years later, he was appointed as Princess Diana’s personal designer. 

When asked about this honour by Irish broadcaster RTE in early 2025, Costelloe recalled, “I looked out at Hyde Park, and I said: ‘God, this is it, Paul, you have made it!’” 

Costelloe dressed Princess Diana in uplifting colours, flamboyant florals and polka dots. See below for some of the outfits he designed.

Princess Diana during the Royal Tour of Oman, 1986

The young princess wears a pink and white floral dress with a white Peter Pan collar. 

Princess Diana in Terrigal, Australia, 1988 

For the Terrigal Beach Surf Carnival, a surf lifesaving carnival, Princess Diana wore a yellow and white dress with shoulder pads. 

Princess Diana during the Royal Visit to Nigeria, 1990