The police have not released an official report on the cause of death, but his press representatives at KCD Worldwide said it was an apparent suicide.
As a designer, McQueen was not only a technical genius -- as comfortable cutting an Edwardian-inspired suit as draping a kimono with a 25-foot train -- but a creative genius as well. His theatrical runway productions were often controversial, casting models as witches, rape victims and mental patients, challenging the notions of what is beautiful and what is grotesque.
He was known for rigorously tailored jackets, second-skin repeating-pattern leggings and dresses, gravity-defying lobster-claw shoes and a fascination with the macabre that lent itself to suitcases with rib-cage motifs and sweaters with cable-knit skulls and crossbones.
"A gifted iconoclast, who could just as easily be creating art as fashion," was how former Times fashion editor Mimi Avins described McQueen upon seeing his clothes for the first time in 1996.
Eric Jennings, vice president and men's fashion director of Saks Fifth Avenue, who was among the buyers and press attending McQueen's Milan menswear show last month, described the designer Thursday as an icon.
"It's a tragedy; Alexander McQueen has been a tremendous resource for us," Jennings said.
Lee Alexander McQueen was born in London on March 17, 1969, the youngest of six children of a London cabdriver and his homemaker wife. He completed his studies at Central Saint Martin's College of Art & Design in 1992, trained with Romeo Gigli in Milan and apprenticed on Savile Row.
He started his women's wear business in 1992, then launched his menswear enterprise in 2004 and the secondary line McQ in 2006.
From 1996 to early 2001, he had a rocky tenure as head designer of the Louis Vuitton Moet Hennessy-owned house of Givenchy. It was so rocky, in fact, that he sold a stake of his own business to rival Gucci Group in 2000.
Soon, McQueen's gothic aesthetic became a favorite of celebrities such as Kate Moss, Gwyneth Paltrow and Rihanna, who wore his skull print silk scarves as often as his evening gowns. Cameron Diaz wore a fuchsia dress by the designer at the recent Golden Globe Awards.
McQueen had boutiques in New York, London, Milan and Las Vegas and on Melrose Avenue in Los Angeles. He received the British Fashion Council's British Designer of the Year award four times, and he was named Commander of the Order of the British Empire, among other honors.
With runway collections inspired by such influences as Dante and the Salem witch trials, McQueen thumbed his nose at convention -- and occasionally, the fashion industry. And lately, he had been on the forefront of combining fashion and new technology.
For his women's runway show in October, he webcast his sci-fi fantasy live through a collaboration with director Nick Knight and Showstudio.com, turning it into an unmediated international event that included the debut of a new song by Lady Gaga.
Death seemed never to be far from McQueen's mind both on the runway and off. In a 2008 interview with The Times the day before his 39th birthday, he said the suicide of his longtime friend and mentor, the eccentric stylist Isabella Blow, had a profound effect on him.
And at what turned out to be his final runway show, the presentation of his fall menswear collection last month in Milan, the macabre was manifested as a repeating photo-realistic print pattern that evoked the neatly stacked piles of bones found in catacombs.
McQueen's death comes days after his mother Joyce's death Feb. 2, and weeks before he was due to present his fall women's collection in Paris. He is survived by his father, Ron, and five siblings, Janet McQueen, Tracey Chapman, Jacqui McQueen, Tony McQueen and Michael McQueen.
Times staff writer Adam Tschorn contributed to this report.