William Poundstone is an American author, columnist, and skeptic. He has written a number of books including the Big Secrets series and a biography of Carl Sagan. He is a cousin of comedian Paula Poundstone.
An enthusiast of Harry Stephen Keeler, he maintains the Keeler homepage and contributed to the anthology A to Izzard: A Harry Stephen Keeler Companion (2002).
- Big Secrets: The Uncensored Truth About All Sorts of Stuff You Are Never Supposed to Know. 1983.
- The Recursive Universe: Cosmic Complexity and the Limits of Scientific Knowledge. 1984. ISBN 978-0809252022.
- Bigger Secrets: More Than 125 Things They Prayed You'd Never Find Out. 1986.
- Labyrinths of Reason: Paradox, Puzzles, and the Frailty of Knowledge. 1988.
- The Ultimate: The Great Armchair Debates Settled Once and for All. 1990.
- Prisoner's Dilemma: John von Neumann, Game Theory, and the Puzzle of the Bomb. 1992. ISBN 978-0385415804.
- Biggest Secrets: More Uncensored Truth About All Sorts of Stuff You Are Never Supposed to Know. 1993.
- Carl Sagan: A Life in the Cosmos. 1999.
- The Big Book of Big Secrets. 2001. reprints Big Secrets and Biggest Secrets
- How Would You Move Mount Fuji? : Microsoft's Cult of the Puzzle—How the World's Smartest Companies Select the Most Creative Thinkers. 2003.
- Fortune's Formula: The Untold Story of the Scientific Betting System That Beat the Casinos and Wall Street. 2005. ISBN 978-0809045990.
- Gaming the Vote: Why Elections Aren't Fair (and What We Can Do About It). 2008.
- Priceless: The Myth of Fair Value (and How to Take Advantage of It). 2010.
- Are You Smart Enough to Work at Google?. 2011.
- Rock Breaks Scissors: A Practical Guide to Outguessing and Outwitting Almost Everybody. 2014. ISBN 978-0316228060.
- Head in the Cloud: Why Knowing Things Still Matters When Facts Are So Easy to Look Up. 2016. ISBN 978-0316256544.