Despite only being 37 herself, the former Spice Girl landed at number six on the poll.
The glamorous singer turned fashion designer was the youngster woman to feature in the top 20 list.
Unsurprisingly, Oscar winner Dame Helen Mirren came top of the pile.
A spokeswoman for clothing brand CC, who carried out the poll, said: “Victoria Beckham has proven she carries universal appeal and her image over the past few years has altered from high glamour to a more classic look which appeals to women of all ages.
“The results show women in their fifties aren’t afraid to embrace younger styles when they’re done the right way.
“And Dame Helen Mirren has as much style, grace and elegance off screen as she does on it and is a fitting icon for the women of her generation.
“All too often we are bombarded with images of youth and temporary trends, so it’s great to see such a varied list filled with women of real class.”
Runner-up was world-renowned model and face of the swinging sixties, Twiggy.
Joanna Lumley, who famously starred in Absolutely Fabulous, was third. Sixties pop sensation Lulu was fourth, while the first lady of British cinema, Dame Judi Dench, was fifth.