Princess Kate's Commonwealth Day mermaid outfit - with glittering nod to Princess Diana
Kate Middleton wearing a white blazer and a navy blue hat, watches a flypast from the balcony of Buckingham Palace during Trooping the Colour on June 2, 2022 in London, England.

The annual Commonwealth Day service will be held at Westminster Abbey on 9 March and and The monarch will also be joined by the the Princess Royal, Vice Admiral Sir Tim Laurence, and over 1,000 other guests.
The Princess of Wales has attended ten Commonwealth Day Services throughout her time as a working royal, and on each occasion, she has delighted onlookers with her formal yet elegant outfits. The royal opts for feminine coats or expertly cut dresses, alongside a fascinator or headpiece.

Her look was both polished and surprisingly modern compared with previous years. In both 2020 and 2022, the wife of Prince William wore Catherine Walker dress coats, in red and blue, that finished at the ankle.

In 2023, she wore a tailored jacket and suit set from fashion designer Erdem. The midi pencil skirt featured a flared, mermaid hem that fanned out elegantly as she walked. This style and her tailored peplum jacket were from the designer's pre-fall 2023 collection.
Both pieces were designed in a navy blue colourway and had delicate embroidered flowers. The pieces were the epitome of modern dressing.

In previous years, Kate has donned stunning headbands and pillbox hats, but that year, she added a classic, circular hat by Sean Barrett, which had a sweeping brim and feminine ribbon trim.