The 40-year-old model - who was discovered at the tender age of 14 - is considered the modern day equivalent of the legendary fashion icon, who started modelling in the 1960s aged just 16.
According to research conducted by Ascot to find the nation's modern day British classics in the fields of fashion, arts, music, beverages and iconic landmarks, Kate topped the poll with 41% of the vote, taking the title from Naomi Campbell and model of the moment, Cara Delevingne.
Twiggy, 64 - whose real name is Lesley Lawson - was famed for her androgynous look and thin frame, and graced the covers of Vogue and Tatler by her late teens.
Similarly, Kate - whose super skinny look was referred to as 'heroin-chic' in the early 90s - has appeared on the cover of British Vogue 30 times throughout her 25-year career.
Ascot commissioned the research to coincide with the prestigious King George Weekend - which is set to take place from 25 to 27 July - and also found that One Direction's 'Up All Night' is the nation's favourite modern British album.
The London Eye took the title of favourite British landmark, while Pimm's was named the nation's preferred drink.
The '12 Years A Slave' director will receive the accolade at the London Film Festival in October.
Critics from all over the world were asked to name the best movie of the past 16 years.