Sheryl Sandberg clearly knows how to command attention: The Facebook Chief Operating Officer's 2013 bestselling book "Lean In: Women, Work, and the Will to Lead" won famous fans (including fellow Power Women Yahoo CEO Marissa Mayer and Beyonce), spawned thousands of Lean In Circles, inspired a spin-off ("Lean In for Graduates," published in 2014) and a Sony Pictures movie deal. With a net worth of just around $1 billion, Sandberg oversees sales, marketing, business development, human resources and communications at the social media giant, which has a $160 billion market value. Under Sandberg's leadership, Facebook has improved its earnings performance and revamped its mobile strategy. In May Sandberg joined The Giving Pledge, promising to give away at least half of her net worth to charitable causes.

She is number 9 on the list.