Infant and early childhood mental health is the foundation on which future emotional and behavioral regulation and relationships are built Early childhood mental health is influenced by multigenerational experiences of caregiving, relationships, and overall well-being. For most children, early experiences support healthy development. For a substantial minority of children, genetics, early caregiving experiences, and/or community contexts contribute to early onset mental health concerns that present with emotional, behavioral, or relational dysregulation. Family-focused early identification, preventive services, and clinical interventions are effective in reducing suffering and clinical impairment. Workforce shortages and systemic barriers to dissemination limit the impact of these effective interventions.