Age: 41
Occupation: Spanx founder
Over the past decade, Blakely has quite literally shaped the lives of thousands of women around the world. After starting Spanx in 2000 with a $5,000 investment, she shopped its stretchy undergarments herself to department-store buyers, ultimately turning the company into a powerhouse with nearly $250 million in revenue a year and more than 200 products sold in 11,000 stores in 40 countries. In 2012 Blakely became the youngest female self-made billionaire to appear on Forbes magazine's annual billionaires list.