William Costelloe presents a collection of modern tailoring, fluid silhouettes and Irish textiles, combining structured design with effortless summer dressing.

Paul Costelloe has unveiled its Spring/Summer 2027 collection at London Fashion Week, marking a new chapter for the fashion house under the creative direction of William Costelloe.
Designed and made entirely in London, the collection explores the balance between precision and ease, bringing together modern tailoring, lightweight fabrics and relaxed silhouettes. The presentation reflects the house’s focus on craftsmanship, creativity and its established heritage.
The show opens with a fox, a tribute to founder Paul Costelloe, brought to life through hand-drawn animation by Nicholas Costelloe. The character explores the materials, artistry, talent and heritage of the fashion house.
Tailoring forms the foundation of the collection, softened by linen, silk and lightweight cotton. The designs move between daytime and evening dressing, with pieces intended to transition from spring into high summer.
The opening looks feature structured biker jackets, cropped silhouettes and statement coats crafted from 100% Italian textured wool. Oversized single- and double-breasted jackets introduce wide, curved lapels, sculpted shoulders and exaggerated proportions.
High-buttoned jackets with specially moulded gold buttons are paired with fluid side-pleated shorts. Elsewhere, elongated trouser lengths and softer silhouettes add movement to the collection’s more architectural tailoring.
Magee striped linens appear across oversized single- and double-breasted jackets, coordinated shorts and longer, wide-leg pleated trousers. The combination brings a more relaxed approach to traditional tailoring.
The collection is complemented by Paul Costelloe bags and accessories, including oversized clutches, raffia totes and east-west bags in tan and navy. Gold buttons feature the Costelloe family crest and the motto Cor Unum, Via Una — “One Heart, One Way” — reflecting the house’s commitment to craftsmanship and creativity.
Crisp blue and white shirting introduces a lighter element, with oversized curved cuffs, statement bows and pleated linen designs. Off-the-shoulder, fine-gauge cotton knits in cream, navy and subtle stripes add softness to the collection’s structured pieces.
The colour palette remains deliberately restrained, featuring navy, cornflower blue, cream, white and soft summer neutrals. This allows the collection’s tailoring and fabric choices to remain central. Thin, double-layered belts in tonal navy and tan define the waist while adding structure to fluid silhouettes.
Silk scarves play a significant role throughout the collection. Hand-drawn by William Costelloe, the designs feature bold statement borders and are styled in a variety of ways, including as headscarves, loosely around the neck and wrapped around handbags. Their versatility reflects the collection’s emphasis on spontaneity and individual styling.
“I wanted this collection to feel chic, effortless and spontaneous,” said William Costelloe. “The design and the fabric should do the work – a beautiful garment, a great bag, a silk scarf worn however you want. No rules.”
For the finale, Costelloe highlights Irish textiles, incorporating fabrics from Ferguson’s Irish Linen and Magee into fluid jumpsuits, sculpted dresses, voluminous shorts and summer tailoring. Signature floral details appear alongside textured linen blends and relaxed silhouettes.

The Spring/Summer 2027 collection places craftsmanship at the centre of William Costelloe’s vision for Paul Costelloe, bringing together precise tailoring, relaxed proportions and a modern approach to summer dressing.
Photos by Paul Winstone
