William Costelloe Reacts to Kate Middleton Wearing Alexander McQueen on St Patrick’s Day

William Costelloe has expressed disappointment over the sartorial choices of Catherine, Princess of Wales, during the St. Patrick’s Day celebrations on March 17, 2026. In a feature for The Irish Independent, Costelloe critiqued the decision to favor the British fashion house Alexander McQueen over the work of Irish designer Paul Costelloe.

The critique centers on the concept of sartorial diplomacy, where members of the royal family often select attire that honors the culture or designers of the country they are celebrating. Costelloe argued that the Princess of Wales possesses an aesthetic that aligns seamlessly with the Paul Costelloe brand.

Kate Middleton is the perfect Paul Costelloe woman, so I was disappointed to see her wearing Alexander McQueen on St Patrick’s Day

William Costelloe, The Irish Independent

The Influence of Alexander McQueen

The Princess of Wales has a well-documented and long-standing professional relationship with Alexander McQueen. The fashion house is frequently her choice for high-profile diplomatic engagements, state visits, and formal royal duties, known for its structured tailoring and modern silhouettes that mirror the Princess’s public image.

However, Costelloe suggests that this reliance on a single fashion house can lead to missed opportunities to highlight regional talent, particularly during events specifically dedicated to Irish heritage.

The Paul Costelloe Aesthetic

Paul Costelloe is recognized as one of Ireland’s most prominent fashion designers, noted for a style that emphasizes timeless elegance and precision tailoring. The brand’s focus on sophisticated, feminine silhouettes is what led William Costelloe to describe the Princess of Wales as the perfect Paul Costelloe woman.

By selecting an Irish designer for St. Patrick’s Day, the Princess could have provided a global platform for Irish craftsmanship. The disappointment expressed by Costelloe highlights a tension between the Princess’s established style preferences and the expectations of cultural representation in royal dressing.

The choice of Alexander McQueen for the March 17 event continues a pattern of the Princess utilizing the brand for moments of significant visibility, even when local alternatives are available and stylistically compatible.

Sartorial Diplomacy in the Royal Wardrobe

The use of fashion as a tool for diplomacy is a cornerstone of royal public appearances. By wearing designers from a specific region or country, royals can signal respect and affinity without the need for verbal statements. This practice is common during official tours and national holidays.

When the Princess of Wales opts for a British brand during an Irish celebration, it can be interpreted by fashion commentators and industry insiders as a departure from this diplomatic tradition. The commentary in The Irish Independent reflects a broader desire within the Irish fashion industry to see its leading designers represented on the world stage through the royal wardrobe.

While the Princess of Wales has worn various designers over her tenure, her frequent returns to Alexander McQueen underscore a preference for the brand’s specific architecture and reliability for high-pressure public events.