The relationship between forensic clinical psychology and the juvenile courts and juvenile justice system is a special one. Psychologists and other mental health professionals have been involved in the juvenile courts since their inception a little over 100 years ago, and some commentators have offered that forensic psychology can trace its roots to psychologists’ involvement in juvenile matters (Otto & Heilbrun, 2002). In this chapter, after providing an overview of the juvenile justice system and its history, we review a number of clinical issues critical to understanding adolescents and their involvement in the juvenile justice system, and we finish with a discussion of the law and clinical factors surrounding evaluation in this context.