Urban agriculture has increased rapidly in the Global North in recent decades. However, because most research has focused on developing countries, we still lack systematic information on the benefits, barriers, costs and risks of the practice of food production in cities of the Global North. Urban horticulture (UH) is the agriculture of plants for food consumption, materials production, or decoration, developed inside city boundaries. UH has recently been proposed as a tool to improve population health and urban biodiversity. This study takes a systems approach to reviewing the literature on the impacts of UH on public health, the environment and health behaviours, using the ecosystem services (ES) concept as lens. Using a scoping review methodology, 138 papers met the search criteria and these studies were used to develop a conceptual framework summarizing and synthesing the direct and indirect pathways in which urban horticulture and public health are interconnected. The resulting “eco”systems-based framework analyses and visualises the relationship between UH and public health and provides evidence for relationships (both positive and negative) between, and pathways linking, urban horticulture and benefits for mental health, physical activity, diet, and socialisation. This study demonstrates that UH can help to improve public health in cities of the Global North and makes the case for UH as a solution to tackling multiple health and societal challenges that arise in urban populations. We provide a framework to enable local authorities and urban stakeholders to maximise the benefits from, and reduce the risks related to, the practice of UH at a systems level.