Keith E. Stanovich (born 1950) is an American research scientist and psychologist. He is an Emeritus Professor of Applied Psychology and Human Development at the University of Toronto and former Canada Research Chair of Applied Cognitive Science. His primary research areas are the psychology of reasoning and the psychology of reading. Stanovich has been acknowledged by his peers as one of the most influential cognitive psychologists in the world. His 2009 book What Intelligence Tests Miss won the 2010 Grawemeyer Award in Education. In 2012, Stanovich received the E. L. Thorndike Career Achievement Award from the American Psychological Association (APA). He is a fellow at the APA, the American Psychological Society, and the Committee for Skeptical Inquiry.

Stanovich initially studied physics in university and only became drawn to psychology when he earned money serving as a paid subject in psychology experiments. He went on to obtain a bachelor of arts from Ohio State University as well as an MA and PhD from the University of Michigan.

Stanovich is an Emeritus Professor of Applied Psychology and Human Development at the University of Toronto and former Canada Research Chair of Applied Cognitive Science. His primary research areas are the psychology of reasoning and the psychology of reading. He has been acknowledged by his peers as one of the most influential cognitive psychologists in the world. His research in the field of reading was "fundamental to the emergence of today's scientific consensus about what reading is, how it works, and what it does for the mind", according to author David Boulton. His research on the cognitive basis of rationality has been featured in the journal Behavioral and Brain Sciences. Boulton purports that Stanovich is "a scientist's scientist and a man whose pioneering work has contributed substantially to both the cognitive science and reading science fields".

Stanovich has done extensive research on reading, language disabilities, and the psychology of rational thought. His article on the Matthew effect in education has been cited over 2,700 times in scientific literature. The Matthew Effect, with respect to education, refers to a research phenomenon regarding how new readers acquire the skills to read. Stanovich has explored the concept as well as the relationship between rationality and intelligence. He is the author of over 200 scientific articles, some of which have become Current Contents Citation Classics. In a 1993 article in the Journal of Learning Disabilities, Stanovich coined the term dysrationalia to refer to the tendency toward irrational thinking and action despite adequate intelligence.

In his 2016 book, The Rationality Quotient: Toward a Test of Rational Thinking, Stanovich and colleagues followed through on the claim that a comprehensive test of rational thinking is scientifically possible, given current knowledge. Stanovich researched people's scores on rationality tests, comparing them with their scores on conventional intelligence tests, and revealed a low correlation between them; on some tasks, he found a near-complete dissociation between rational thinking and intelligence.

Stanovich theorizes that the thinking mind consists of three parts:

In a three-year survey of citation rates during the mid-1990s, Stanovich was listed as one of the fifty most cited developmental psychologists. He has also been named one of the 25 most productive educational psychologists. In a citation survey of the period 1982–1992, he was designated the most cited reading disability researcher in the world.

Stanovich is a fellow of the American Psychological Association (APA), the American Psychological Society, and the Committee for Skeptical Inquiry. From 1986 to 2000, he was the associate editor of Merrill-Palmer Quarterly, a human development journal.