Thomas M. Siebel is an American businessman, technologist, and author. He founded the enterprise software company Siebel Systems and was the founder, chairman, and former CEO of C3.ai, an artificial intelligence software platform and applications company.
Adapted from Wikipedia (CC BY-SA 4.0).
Each figure is a dated estimate from the publisher shown; wealth changes, and nothing here is live.
| As of | Estimate | Source |
|---|---|---|
| 2025 | $4.1B | Forbes · current |
Every fact on this page traces to one of these.
Also born on November 20
Politician
1942 · United States
Joseph Robinette Biden Jr. is an American retired politician who was the 46th president of the United States from 2021 to 2025.
Adam Schultz, Public domain, via Wikimedia Commons
Entrepreneur · Turning Point USA
1988 · United States
Erika Lane Kirk is an American businesswoman, nonprofit executive, and podcaster. She serves as chairwoman and CEO of Turning Point USA (TPUSA), a conservative organization co-founded and led by her late husband, Charlie Kirk, until his assassination in September 2025.
Politician
1925–1968 · United States
Robert Francis Kennedy, also known by his initials RFK, was an American politician and lawyer.
Harry Warnecke, Public domain, via Wikimedia Commons
Author
1923–2014 · South Africa
Nadine Gordimer was a South African writer and political activist. She received the Nobel Prize in Literature in 1991, recognised as a writer "who through her magnificent epic writing has. been of very great benefit to humanity".
Boberger. Photo: Bengt Oberger, CC BY 3.0, via Wikimedia Commons
Author
1858–1940 · Sweden
Selma Ottilia Lovisa Lagerlöf was a Swedish writer. She published her first novel, Gösta Berling's Saga, at the age of 33. She was the first woman to win the Nobel Prize in Literature, which she was awarded in 1909.
https://www.nobelprize.org/nobel_prizes/literature/laureates/1909/lagerlof-facts.html, Public domain, via Wikimedia Commons
Scientist
1886–1982 · Austria
Karl Ritter von Frisch was a German-Austrian ethologist who received the Nobel Prize in Physiology or Medicine in 1973, along with Nikolaas Tinbergen and Konrad Lorenz.
Stefanie Ludwig, Public domain, via Wikimedia Commons