We present findings based on several of our recent studies that have shown that father engagement has significant effects on children's cognition and language at 24 and 36 months and their social and emotional development at 24, 36 months, and pre-Kindergarten. These studies are guided by the Dynamics of Paternal Influences on Children over the Life Course Model that stipulates the important contribution of parent characteristics, child and context to parenting and children's outcomes. Specifically, three research questions are addressed: (1) How do resident fathers engage with their young children at 24, 36, and 64 months (pre-K)? (2) How do fathers' human and financial resources and depressive symptoms, partner relationship quality and mother-child interactions, and children's characteristics predict the quality of fathers' engagements with their young children? And (3) how do fathers' engagements affect their young children's cognitive, language, and social and emotional outcomes across the three age groups? Educated fathers and fathers whose partners have supportive relationships with their children are more supportive and less intrusive. In contrast to mothers, fathers' supportiveness matters for children's language, cognitive, and language development across ages and emotional regulation at 24 months. On the other hand, maternal intrusiveness is negatively associated with emotional regulation at 24 and pre-K and language development at pre-K. Father intrusiveness had a small negative effect on language development only at pre-K and no effect at all on social emotional regulation. These findings suggest that programs that aim at increasing fathers' education and that promote and encourage fathers' positive parenting will yield large benefits for children.