Cognitive behavioral therapy (or cognitive behavior therapy, CBT) is a psychotherapeutic approach that aims to influence dysfunctional emotions, behaviors and cognitions through a goal-oriented, systematic procedure. CBT can be seen as an umbrella term for a number of psychological techniques that share a theoretical basis in behavioristic learning theory and cognitive psychology.

There is empirical evidence that CBT is effective for the treatment of a variety of problems, including mood, anxiety, personality, eating, substance abuse, and psychotic disorders. Treatment is often brief, and time-limited. CBT is used in individual therapy as well as group settings, and the techniques are often adapted for self-help applications. Some CBT therapies are more orientated towards predominantly cognitive interventions, while others are more behaviorally orientated.

In recent years, cognitive behavioral approaches have become widespread in correctional settings. These programs are designed to teach offenders cognitive skills that may reduce criminal behaviors. In many countries, it has become commonplace to find cognitive behavioral program strategies in use in prisons and jails. In cognitive orientated therapies, the objective is typically to identify and monitor thoughts, assumptions, beliefs and behaviors that accompany and are related to negative emotions, and to identify those which are dysfunctional, inaccurate, or unhelpful. The aim is to replace or transcend them with those which are more realistic and useful.

CBT was primarily developed through a merging of behavior therapy with cognitive therapy. While rooted in rather different theories, these two traditions found common ground in focusing on the "here and now", and on alleviating symptoms. Many CBT treatment programs for specific disorders have been evaluated for efficacy and effectiveness; the health-care trend of evidence-based treatment, where specific treatments for symptom-based diagnoses are recommended, has favored CBT over other approaches such as psychodynamic treatments. In the United Kingdom, the National Institute for Health and Clinical Excellence recommends CBT as the treatment of choice for a number of mental health difficulties, including post-traumatic stress disorder, OCD, bulimia nervosa and clinical depression.