Fathers are critical stakeholders in childhood obesity prevention but are difficult to engage. This review presents a new approach to engaging fathers in obesity prevention during the first 1,000 days. The review focuses on five existing health and social service programs, including prenatal care, pediatric care, the Special Supplemental Nutrition Program for Women, Infants, and Children, home visiting, and Early Head Start. For each program, the obesity prevention services provided, evidence of father engagement, and barriers thereto are outlined. Subsequently, policy, systems, and environmental strategies are outlined to address the noted barriers and promote father engagement. Although the programs hold great promise in bringing obesity prevention services to fathers, barriers to their engagement are present in the inner (e.g., limited hours of operation, lack of fatherā€specific materials and programming) and outer (e.g., lack of model programs, best practice models, and consistent funding) settings of programs. Policy, systems, and environmental strategies to increase father engagement focus on earmarked funding, changes to national practice guidelines and practitioner training requirements, and the establishment of fatherā€engagement performance metrics. Increasing father involvement in the specified programs will likely increase their engagement in early obesity prevention in an efficient and sustainable manner.