American businessman Thomas Siebel has an estimated net worth of $2.2 billion as of April 2016 according to Forbes. He is known to be the Chief Executive Officer, Chairman and founder of C3. He is also the current chairman of First Virtual Group which holds interests in agribusiness, philanthropy, commercial real estate and investment management.

Thomas Siebel was born on November 20, 1952 in Chicago, Illinois. Currently based in Woodside California, Siebel is a B.A graduate in history from the University of Illinois at Urbana-Champaign as well as a master's degree in Computer Science. He is currently married to Stacey Siebel with whom he has four children.

In the past, he has worked for Oracle Corporation as an executive from 1984 through 1990. He has also worked as a CEO for Gain Technology which is a multimedia software company. He was also the Chairman, CEO and founder of Siebel Systems.

He was ranked fifth and third in the Barron's list of World's Top 25 Philanthropists in 2009 and 2010 respectively. In 2007 and 2008, he was named by Businessweek as one of The 50 Most Generous Philanthropists. Meanwhile, he was named by Ernst & Young as the Master Entrepreneur of the Year in 2003.