(1) Background: This study aims to examine and describe the policies of three Latin American countries: Colombia, Brazil, and Spain, and identify how they implement their support systems for health, mental health, mental health for children and adolescents, and juvenile justice systems that support judicial measures with treatment and/or therapeutic approaches specialized in mental health. (2) Methods: Google Scholar, Medline, and Scopus databases were searched to identify and synthesize of the literature. (3) Results: Three shared categories were extracted to construct the defining features of public policies on mental health care in juvenile justice: (i.) models of health and mental health care, (ii.) community-based child and adolescent mental health care, and (iii.) mental health care and treatment in juvenile justice. (4) Conclusions: Juvenile justice in these three countries lacks a specialized system to deal with this problem, nor have procedures been designed to specifically address these situations within the framework of children’s rights.