A growing body of literature highlights the important role of paternal health and socioemotional characteristics in child development, from preconception through adolescence. Much of this research addresses the indirect effects of fathers, for instance, their influence on maternal behaviors during the prenatal period or via the relationship with their partner. However, emerging evidence also recognizes the direct role of paternal health and behavior for child health and adjustment across development. This critical review presents evidence of biological and sociocultural influences of fathers on preconception, prenatal, and postnatal contributions to child development. The National Institutes of Health Environmental influences on Child Health Outcomes (ECHO) program incorporates in its central conceptualization the impact of fathers on family and child outcomes. This critical synthesis of the literature focuses on three specific child outcomes in the ECHO program: health outcomes (e.g., obesity), neurodevelopmental outcomes (e.g., emotional, behavioral, psychopathological development), and positive health. We highlight the unique insights gained from the literature to date and provide next steps for future studies on paternal influences.