Nassim Nicholas Taleb is a Lebanese-American essayist, mathematical statistician, former option trader, risk analyst, and aphorist. His work concerns problems of randomness, probability, complexity, and uncertainty.

Taleb is the author of the Incerto, a five-volume work on the nature of uncertainty published between 2001 and 2018, notably including The Black Swan and Antifragile. He has taught at several universities, serving as a Distinguished Professor of Risk Engineering at the New York University Tandon School of Engineering since September 2008. Taleb has also been a practitioner of mathematical finance and is currently an adviser at Universa Investments.

The Sunday Times described his 2007 book The Black Swan as one of the 12 most influential books since World War II. Taleb has criticized risk management methods used by the finance industry and warned about financial crises, subsequently profiting from the Black Monday (1987) and the 2007–2008 financial crisis. He advocates for a "black swan robust" society, meaning a society that can withstand difficult-to-predict events.

He proposes what he has termed "antifragility" in systems; that is, an ability to benefit and grow from a certain class of random events, errors, and volatility, as well as "convex tinkering" as a method of scientific discovery. By this, he suggests that decentralized experimentation outperforms directed research.