Existing research has built concrete links between trauma exposure and lifelong behavioral health outcomes. However, the ways by which father engagement buffers the detrimental effects of trauma on early childhood behavioral health remains unexplored. Using the data of 3001 mothers from the Fragile Families and Child Well-being Study, we conducted a moderation analysis to examine the associations between adverse childhood experiences (ACEs), child behavioral health, father engagement, and maternal education. We found that ACEs at child age three were positively associated with child externalizing and internalizing behaviors at child age five. Father engagement at child age one buffered the harmful effects of ACEs on child externalizing behaviors, but this effect was only significant for children living with mothers with an education level lower than high school. Child psychiatrists should view father engagement as a critical factor in fostering child resilience, particularly for children living in families with limited resources.