Sara Blakely

Sara Blakely was 29 when she invested her entire life savings, $5,000, trying to come up with something flattering to wear under her white slacks. Six months later, the one-time Disney World ride greeter and door-to-door fax machine salesperson found her new line of shaping underwear, Spanx, named one of Oprah Winfrey's Favorite Things. Since then, Blakely has taken Spanx from a one-product wonder sold out of her Atlanta apartment to a billion-dollar powerhouse with just under $250 million in annual revenues and net profit margins estimated at 20%. She owns 100% of the private company, has never advertised and never taken outside investment. Blakely turned 41 in February, making her the youngest female self-made billionaire in the world. Bachelor of Arts / Science, Florida State University