Infant and early childhood mental health interventions and treatment take place in many different settings including clinics serving adults and children, primary care centers, pediatric clinics, private practice offices, homes, early intervention offices, and child care centers. In addition, the types of evaluations and services offered in these settings will vary depending on who is included in the intervention; time spent with the child, parent, or both; and types of assessment, intervention, and treatment. The setting for the intervention is often related to when and where the problem is identified. In this article, four authors describe programs that represent the diversity within the training, interventions, and treatments for infants, toddlers, and their families, and the importance of integrating a socio-cultural and diversity-informed perspective in this important work.