The Olympic gold medalist showed off her toned figure in a dress by Stella McCartney - who was also at the awards - and was joined by Team GB's Victoria Pendleton and Paralympian Ellie Simmonds.
Pendleton went for a printed, midnight-blue dress, while model Daisy Lowe and Gillian Anderson both looked elegant in vintage-style gowns.
Also at the event were actresses Emily Blunt who stood out in a tangerine halterneck dress, Marion Cotillard in a strapless black gown and Rosamund Pike in a long, one-shouldered frock.
Model David Gandy arrived looking suited and booted with his girlfriend Sarah Ann Macklin, while husband and wife team Sophie Dahl and Jamie Cullum were also on the red carpet.
The Queen was honoured with the 'Icon of the Year' title, but declined the offer of a night out.
Stella McCartney British Designer of the Year
Marion Cotillard International Actor of the Year
The Queen Icon of the Year
Jessica Ennis, Victoria Pendleton and Ellie Simmonds British Ambassadors of the Year
Dame Vivienne Westwood Inspiration of the Year
Raf Simons Man in a Woman's World
Anya Hindmarch Businesswoman of the Year
Ruth Wilson Breakthrough of the Year
Cindy Sherman Artist of the Year
Emily Blunt British Actor of the Year
Emeli Sande Musician of the Year
Marie Colvin In Memoriam