Steven C. Hayes (born 1948)^[1] is Nevada Foundation Professor at the Department of Psychology at the . He is known for an analysis of human language and cognition (Relational Frame Theory), and its application to various psychological difficulties (his work on ).

Hayes' work is somewhat controversial, and in 2006 was the subject of a lengthy story in Time magazine,^[1] as well as related stories in the popular media around the world including Salon.com,^[2] the Brazilian news magazine Veja, the German magazine Emotion, Oprah's magazine O, and other such outlets. His popular book Get Out of Your Mind and Into Your Life, rose to #20 on the Amazon.com list of all books in early 2006, and became the #1 self-help book in the US for a month, for a time outselling "Harry Potter" on Amazon. What seems to be most controversial, at least in the popular media (as is shown by the title of the piece in Time: "Happiness Isn't Normal"), is his claim that pain is ubiquitous and dominantly linked to normal language processes rather than abnormality. This has in particular placed Acceptance and Commitment Therapy somewhat at odds with mainstream Cognitive Behavior Therapy and empirical clinical psychology, despite the fact that Acceptance and Commitment Therapy is a form of behavioral and cognitive therapy. A number of similar methods have recently emerged in cognitive behavior therapy, however, including Dialectical Behavior Therapy and Mindfulness-based Cognitive Therapy, suggesting that there is an ongoing struggle between traditional and new methods.