Physical activity engagement during childhood is associated with positive health outcomes in adulthood. Exercise and sport science research links physical activity enjoyment with physical activity adoption and maintenance, among other positive health behaviors. However, public health researchers rarely measure enjoyment or discuss its role in interventions or theory. In this paper, we present the rationale for bringing enjoyment to the forefront of public health dialogue and action to increase physical activity in children and across the life course. We outline five potential explanations for the lack of physical activity enjoyment research in public health, and offer solutions and action steps for each. Enjoyment research has the potential to improve people's health by working on multiple levels, from individuals to schools to public sectors, and could have positive implications for various health behaviors.