This article highlights infant and early childhood mental health consultation (IECMHC) as a promising approach to support the social and emotional learning (SEL) of both young children and their adult caregivers in early care and education (ECE) settings (i.e., childcare, Head Start, preschool). IECMHC is “a problem-solving and capacity-building intervention implemented within a collaborative relationship between a professional consultant with mental health training and expertise and one or more consultees” (Cohen & Kauffman, 2005). IECMHC is an increasingly common intervention in ECE settings, including in Head Start programs, where it is federally mandated; however, some confusion persists about the key components, strategies, and outcomes of high-quality IECMHC. Meanwhile, public understanding of the importance of interventions that support SEL starting in early life is also growing. However, little peer-reviewed work has attempted to integrate research and practice in the fields of IECMHC (which has largely existed in infant mental health spaces) and SEL (much of which has historically focused on middle childhood and beyond). To that end, this article: (a) highlights SEL as a developmental and relational process in infancy and early childhood; (b) describes IECMHC as a preventive and promotive intervention to support young children and their caregivers; (c) describes key evidence supporting IECMHC’s effects on adult and child SEL; (d) presents a novel visual conceptualization and case example illustrating the processes by which IECMHC supports adult and child SEL in ECE settings; and (e) proposes future directions for research, practice, and policy in integrating IECMHC and SEL initiatives.