Dion Lee was born on 2 October 1985 and found fashion at high school, at the Newtown School of Performing Arts, where he acquired his first sewing machine and began making clothes for friends, often by taking apart vintage pieces and rebuilding them. He went on to the Fashion Design Studio at TAFE NSW, graduating in 2008. While studying he worked at Robby Ingham's boutique in Paddington, where he examined the inner construction of clothes by Comme des Garçons, Jil Sander and Maison Martin Margiela.
He presented his first collection at Australian Fashion Week in 2009. A year later he became the first designer to stage a runway show at the Sydney Opera House, with sculptural pieces in which pleated fabric was worked into woven, cord-like structures that echoed the building's sails. The show set out what would become his signatures: precise, engineered tailoring, a sleek futurism and a restrained sensuality.
Awards followed quickly. In 2010 he won the Woolmark Designer Award at the Melbourne Fashion Festival and the Qantas Spirit of Youth Award for fashion design. In 2013 he represented Australia at the first International Woolmark Prize and won both the Prix de Marie Claire for Best Australian Fashion Designer and GQ's Best Designer. In 2017 he was named Australian Fashion Laureate, and he was commissioned to design new uniforms for the Sydney Opera House.
Lee took the label abroad early, showing at London Fashion Week in 2012 and on the New York calendar from 2013. American Vogue singled out his Fall 2016 collection for its volume and crystal-embellished fabrics. Commercially, he partnered with the Australian retailer Cue, which collaborated with him from 2011 and became majority shareholder.
In October 2018, the Duchess of Sussex wore a custom Dion Lee dress in Melbourne, and the demand crashed the label's website. Later collections explored corsetry, harnessing and hardware, among them a 2023 show built around ideas of shedding and the serpent. He has cited weather radar, labyrinths, the ZERO group of Heinz Mack, Günther Uecker and Otto Piene, and the architecture of Tadao Ando among his influences.
In May 2024 the business entered voluntary administration, with six stores in Australia and one in the United States; in August it was reported that no buyer had been found and the company would be wound up. At that point the Cue Clothing Company owned 70 per cent of the business. Lee had opened a store in Miami in 2023, was preparing a New York flagship and had shown his Fall 2024 collection in Shanghai a month before the administration. The Dion Lee brand was subsequently acquired by the American retailer Revolve. In November 2025 Lee, by then living between Los Angeles and France, launched HÆLO, a new label under his creative direction, backed by Revolve and sold through Revolve and FWRD. Its first collection kept his signature cut-outs and sheer panels while introducing softer draped silks and lace, built around ideas of the halo, the gothic and "an afterlife of my own brand". He has said a future label under his own name is something he is "exploring for the distant future". He has also dressed Rosalía for her Motomami tour.