18. Eric Schmidt
Net worth: $9.1 billion
Google's executive chairman Eric Schmidt was the CEO of Google from 2001 to 2013 when it became the most widely used online search engine in the world. The 59-year-old Schmidt has since sold off some of his holdings with the company, but he still owns more than 4.5 million shares of Google stock.
Schmidt earned an electrical engineering degree from Princeton and a Ph.D. in computer science from U.C. Berkeley before working in software at Bell Labs and Xerox PARC. Just prior to Google, Schmidt was the CEO of multinational software and services company Novell for four years. Forbes ranks Schmidt as the 137th richest person in the world.