Herbert Alexander Simon (June 15, 1916 – February 9, 2001) was an American psychologist whose research ranged across the fields of cognitive psychology, computer science, public administration, economics, management, philosophy of science and sociology and was a professor, most notably, at Carnegie Mellon University. With almost a thousand often very highly cited publications he is one of the most influential social scientists of the 20th century.

Simon was a polymath, among the founding fathers of several of today's important scientific domains, including artificial Intelligence, information processing, decision-making, problem-solving, attention economics, organization theory, complex systems, and computer simulation of scientific discovery. He coined the terms bounded rationality and satisficing, and was the first to analyze the architecture of complexity and to propose a preferential attachment mechanism to explain power law distributions.

He also received many top-level honors later in life. These include: the ACM's Turing Award for making "basic contributions to artificial intelligence, the psychology of human cognition, and list processing" (1975); the Nobel Memorial Prize in Economics "for his pioneering research into the decision-making process within economic organizations" (1978); the National Medal of Science (1986); and the APA's Award for Outstanding Lifetime Contributions to Psychology (1993).

As a testament to his interdisciplinary approach, Simon was affiliated with such varied Carnegie Mellon departments as the School of Computer Science, Tepper School of Business, Departments of Philosophy, Social and Decision Sciences, and Psychology.