Leo Katz earned his B.A. from the University of Chicago in 1979. He earned both a master's degree in economics and a J.D. from that same institution in 1982. He graduated with honors and earned the Order of the Coif.

He was a Law Clerk to the Hon. Anthony M. Kennedy on the United States Court of Appeals for the Ninth Circuit. He then joined Mayer, Brown and Platt as an associate.

In 1987, he joined the faculty of the University of Michigan Law School. Four years later, he joined the faculty of Penn Law as a professor and in 2004 was named the Frank Carano Professor of Law.

Katz's work focuses on criminal law, and his explorations of the paradoxes of criminal law and deontological theory help facilitate a deeper understanding of philosophical and legal issues. For example, by investigating crimes of coercion and deception, economic crimes like tax evasion, and crimes without apparent victims, he tries to shed light more generally on problems of consent, the use and abuse of legal stratagems, and the nature of harm throughout the law.

Katz was awarded a Guggenheim fellowship for his on-going book project, The Perverse Logic of Law and Morality. Katz has also authored numerous articles for law journals, as well as for the New York Times, Wall Street Journal, National Law Journal, and The American Lawyer. His is married to Penn Law (and Philosophy) professor Claire Finkelstein and has two daughters.