Urban green and blue spaces (UGBS) have the potential to improve public health and wellbeing, address health inequities, and provide co-benefits for the environment, economy, and society. To achieve these ambitions, researchers should engage with communities, practitioners, and policy makers in a virtuous circle of research, policy, implementation, and active citizenship using the principles of co-design, co-implementation, co-evaluation, and co-translation. This Viewpoint provides an integrated perspective on the challenges that hinder the delivery of health-enhancing UGBS and recommendations to address them. Our recommendations include: strengthening the evidence beyond cross-sectional research designs, strengthening the evidence base on UGBS intervention approaches, evaluating the effects on diverse population groups and communities, addressing inequities in the distribution and quality of UGBS, accelerating research on blue space, providing evidence for environmental effects, incorporating co-design approaches, developing innovative modelling methods, fostering whole-system evidence, harnessing political drivers, creating collaborations for sustainable UGBS action, and advancing evidence in low-income and middle-income countries. The full potential of UGBS as public health, social, economic, and environmental assets is yet to be realised. Acting on the research and translation recommendations will aid in addressing these challenges in collaboration with research, policy, practice, and communities.