25-year-old Cole is the first female celebrity from the UK to get to the top of the annual chart in the last three years.
The poll, which is celebrating its 15th year, involved almost 10 million votes in total.
Meanwhile, American pop singer Britney Spears went up from number 31 to fourth place with the help of her fans.
Cole had already been named as the world's best dressed woman by Glamour magazine earlier on this month, but last year she was in seventh place.
Jessica Alba, who had been the winner in 2007, was in third position, and Slumdog Millionaire actress Freida Pinto entered the chart at number 10.
