The field of psychology and law involves the application of scientific, clinical, and policy aspects of psychology to issues that arise in the legal system. Diverse perspectives are encompassed within psychology and law, including most of the major subdivisions in psychology (e.g., cognitive, developmental, industrial/organizational, and clinical). So, for example, cognitive psychologists may examine the reliability of eyewitness memory; developmental psychologists may assess the impact of maltreatment and abuse on social and cognitive development; industrial/organizational psychologists may investigate how workplace conditions contribute to the incidence of sexual harassment; and clinical forensic psychologists may provide assessment and treatment services to courts and attorneys, law enforcement agencies, or offenders in correctional settings or under court supervision. In each of these instances, psychologists use research and/or treatment protocols relevant to their specialization to address specific questions that emerge in the law. This article is organized around the intersection of those traditional subdivisions of psychology and the law. The field of psychology and law values contributions from professionals in a variety of different settings including university and research organizations, clinical practice, law enforcement agencies, correctional institutions, and other governmental and nonprofit agencies. It also values the contributions of professionals from across the globe, and associations devoted to psychology and law now exist in the United States, Canada, Europe, Australia, and New Zealand. Several specialized journals and book series are devoted exclusively to psycholegal matters. Undergraduate courses in psychology and law are increasingly common on college and university campuses. Various training programs prepare graduate and postgraduate students to address mental health issues in a variety of legal settings and to become the next generation of researchers, scholars, and practitioners. The American Board of Forensic Psychology and comparable organizations in other countries credential psychologists who specialize in clinical forensic issues, and an updated set of ethical guidelines has been developed specifically for their use. Psychologists have been involved in appellate court decisions by testifying in hearings and by making their research findings and policy analyses available to judges through amicus briefs submitted to the US Supreme Court and to lower courts.