The Psychopathy Checklist or Hare Psychopathy Checklist-Revised, now the Psychopathy Checklist—revised (PCL-R), is a psychological assessment tool that is commonly used to assess the presence and extent of psychopathy in individuals—most often those institutionalized in the criminal justice system—and to differentiate those high in this trait from those with antisocial personality disorder, a related diagnosable disorder. It is a 20-item inventory of perceived personality traits and recorded behaviors, intended to be completed on the basis of a semi-structured interview along with a review of "collateral information" such as official records. The psychopath tends to display a constellation or combination of high narcissistic, borderline, and antisocial personality disorder traits, which includes superficial charm, charisma/attractiveness, sexual seductiveness and promiscuity, affective instability, suicidality, lack of empathy, feelings of emptiness, self-harm, and splitting (black and white thinking). In addition, sadistic and paranoid traits are usually also present.

The PCL was originally developed in the 1970s by Canadian psychologist Robert D. Hare for use in psychology experiments, based partly on Hare's work with male offenders and forensic inmates in Vancouver, and partly on an influential clinical profile by American psychiatrist Hervey M. Cleckley first published in 1941.

An individual's score may have important consequences for their future, and because the potential for harm if the test is used or administered incorrectly is considerable, Hare argues that the test should be considered valid only if administered by a suitably qualified and experienced clinician under scientifically controlled and licensed, standardized conditions. Hare receives royalties on licensed use of the test.

In psychometric terms, the current version of the checklist has two factors (sets of related scores) that correlate about 0.5 with each other, with Factor One being closer to Cleckley's original personality concept than Factor Two. Hare's checklist does not incorporate the "positive adjustment features" that Cleckley did.

The PCL-R is used for indicating a dimensional score, or a categorical diagnosis, of psychopathy for clinical, legal, or research purposes. It is rated by a mental health professional (such as a psychologist or other professional trained in the field of mental health, psychology, or psychiatry), using 20 items. Each of the items in the PCL-R is scored on a three-point scale according to specific criteria through file information and a semi-structured interview.

The scores are used to predict risk for criminal re-offense and probability of rehabilitation.

The current edition of the PCL-R officially lists three factors (1.a, 1.b, and 2.a), which summarize the 20 assessed areas via factor analysis. The previous edition of the PCL-R listed two factors. Factor 1 is labelled "selfish, callous and remorseless use of others". Factor 2 is labelled as "chronically unstable, antisocial and socially deviant lifestyle". There is a high risk of recidivism and mostly small likelihood of rehabilitation for those who are labelled as having "psychopathy" on the basis of the PCL-R ratings in the manual for the test, although treatment research is ongoing.

PCL-R Factors 1a and 1b are correlated with narcissistic personality disorder. They are associated with extraversion and positive affect. Factor 1, the so-called core personality traits of psychopathy, may even be beneficial for the psychopath (in terms of nondeviant social functioning).