Billionaire Profile
Thomas Siebel
Global Rank
#1093

Image: C3 Energy | CC BY-SA 1.0 | via Wikimedia Commons

Thomas Siebel

CEO, Business software
UNITED STATES
Real-Time Net Worth
$3.955B
Estimated based on Business software stock value as of April 20, 2026
0% (24h)
Age
73
Source
Business software
Industry
Technology
Citizenship
UNITED STATES

Biography

Thomas Siebel is an American businessman, technologist, and author, best known for founding Siebel Systems, a pioneer in customer relationship management (CRM) software, and C3.ai, an enterprise artificial intelligence (AI) software platform. With an estimated net worth of $3.9 billion, Siebel's wealth stems from his ventures in business software and his continued leadership at C3.ai. His career began at Oracle before launching Siebel Systems, which he later sold to Oracle for $5.8 billion. He is recognized for his leadership in technology and his philanthropic efforts, including the Siebel Foundation. Siebel, who is 73 years old as of March 25, 2026, continues to influence the tech industry through C3.ai and his investments in education and research.

Fact Checked
Verified by Editorial Team
Live Data
Updated 4/20/2026

Wealth Over Time

In-Depth Profile

Early Life and Education

Thomas M. Siebel was born on November 20, 1952, in Chicago, Illinois. He grew up in an upper-middle-class family and attended Shattuck Military Academy. Siebel later graduated from the University of Illinois Urbana-Champaign with a B.A. in History, an M.B.A., and an M.S. in Computer Science. He also earned an honorary doctorate in engineering from the same university.

Rise to Success

Siebel began his career at Oracle Corporation, where he held various management positions between 1984 and 1990. He then served as CEO of Gain Technology before co-founding Siebel Systems in 1993. Under his leadership, Siebel Systems became a global leader in customer relationship management (CRM) software, employing over 8,000 people in 29 countries. Siebel Systems was acquired by Oracle in January 2006 for $5.8 billion. In 2009, Siebel founded C3.ai, an enterprise AI software company, where he served as CEO until September 2025, and is now the Executive Chairman.

Key Business Strategies

Siebel is known for his pioneering work in customer relationship management (CRM) software and his ability to identify and capitalize on emerging technology trends. His focus on enterprise AI at C3.ai reflects a strategy to leverage the power of big data, cloud computing, and predictive analytics to provide solutions for various industries. C3.ai's approach involves developing a platform and applications for rapidly developing and operating enterprise-scale AI solutions.

Philanthropy

Siebel established the Siebel Foundation in 1996, which supports initiatives in education, public health, and energy solutions. He has donated millions to his alma mater, the University of Illinois Urbana-Champaign, including the Siebel Center for Computer Science and the Siebel Center for Design. The Siebel Foundation is also involved in combating methamphetamine abuse.

Career Milestones

1984

Joined Oracle

Held various management positions at Oracle Corporation.

1993

Founded Siebel Systems

Founded Siebel Systems, a CRM software company.

2006

Siebel Systems Acquired

Siebel Systems was acquired by Oracle for $5.8 billion.

2009

Founded C3.ai

Founded C3.ai, an enterprise AI software company.

2025

Transitioned to Executive Chairman

Transitioned to Executive Chairman of C3.ai.

Philanthropy & Social Impact

Education

Siebel Scholars Foundation

$0

Supports education and research programs.

Public Health

The Meth Project

$0

Combats methamphetamine abuse.

Education

University of Illinois Urbana-Champaign Donations

$150M+

Major gifts for computer science and design programs.

Business Philosophy & Leadership

Notable Quotes

"History will look back unkindly at social networks, they need to be regulated before they destroy the roots of freedom and democracy.”"

Leadership Principles

Vision

Identifying and capitalizing on emerging technology trends.

Innovation

Pioneering work in software development and customer relationship management.

Philanthropy

Supporting education, health, and energy solutions through the Siebel Foundation.

Controversies & Challenges

2022

Donation to Canadian Convoy Protest

Donated $90,000 to the Canada convoy protest.

2024

Donation to Donald Trump's Re-election Campaign

Donated $500,000 to Donald Trump's re-election campaign.

2025

Opposition to Proposition 50

Donated $1 million toward efforts opposing California's Proposition 50.