Sir Paul McCartney's daughter, who created the kit worn by Great Britain's 2012 Olympics team, was named Designer Of The Year and also landed the Designer Brand prize.
Cara Delevingne was victorious in the Model Of The Year category, Alexa Chung bagged the British Style honour and Harold Tillman, chairman of the British Fashion Council, won the Special Recognition award.
Rita Ora performed at the prizegiving, which was attended by stars including Salma Hayek and pregnant pop star Lily Rose Cooper, formerly known as Lily Allen, who showed off her burgeoning baby bump in a long, blue dress.
Meanwhile, actress Lily Collins made her red carpet debut with rumoured boyfriend Jamie Campbell Bower at the bash.
The couple was first linked in July (12), a month after it emerged Bower had split from his fiancee, Harry Potter star Bonnie Wright.