This briefing paper explores research on the role of fathers and the influence they can have on their child’s emotional and behavioural development. It looks at the influence of fathers through their direct interactions with children, and the indirect influence they have, such as by providing emotional support to their partners. It identifies of aspects of fatherhood associated with good child mental health, which include engagement and communication with children; attachment; accessibility; boundary setting; and the relationships they build within the family. It also looks at barriers to effective fatherhood and the impacts of negative paternal behaviours on a child's welfare. It reports that initiatives which build the self-confidence, motivation and potential contributions of fathers can be effective. It calls for more to be done to recognise the protective potential of fathers to children’s mental health and provide more support for fathers.