Research suggests that many fathers struggle balancing hegemonic masculine norms with new fatherhood ideals. This study uses data on 2,194 fathers from a national study on fathers of children aged 2 to 18 and incorporates a comprehensive assessment of masculine norms to examine whether adherence to masculine norms is associated with father involvement and whether this relationship is mediated by fathers' adherence to the new fatherhood ideal that promotes engaged, nurturing parenting. Results suggest that fathers who more closely adhere to masculine norms are less involved in instrumental and expressive parenting and are more likely to engage in harsh discipline than fathers who are less masculine. Adherence to masculine norms also reduces the likelihood of embracing the new fatherhood ideal, and adherence to the new fatherhood ideal at least partially mediates the relationship between masculinity and father involvement. Overall, despite changing expectations for fathers, hegemonic masculine norms continue to shape fathers' behavior.