Harvey Friedman (born 23 September 1948) is a mathematical logician at Ohio State University in Columbus, Ohio. He has worked on reverse mathematics, a project intended to derive the axioms of mathematics from the theorems considered to be necessary. In recent years this has advanced to a study of Boolean relation theory, which attempts to justify large cardinal axioms by demonstrating their necessity for deriving certain propositions considered "concrete".
Friedman earned his Ph.D. from the Massachusetts Institute of Technology in 1967, with a dissertation on Subsystems of Analysis. His advisor was Gerald Sacks. Friedman received the Alan T. Waterman Award in 1984. He delivered the Tarski Lectures in 2007.
In 1967, Friedman was listed in the Guinness Book of World Records for being the world's youngest professor when he taught at Stanford University at age 18 as an assistant professor of philosophy. He has also been a professor of mathematics and a professor of music. He officially retired in July 2012.
Friedman is the brother of mathematician Sy Friedman.
- L. A. Harrington et al., eds., Harvey Friedman's research in the foundations of mathematics, Studies in Logic and the Foundations of Mathematics 117, Amsterdam, North-Holland Publishing Company (1985)