While climate change is a global challenge, its impact is generally felt in local communities, particularly cities. The impact of climate change in urban settings is exacerbated by the built environment, high energy usage, air pollution and urbanisation, among other factors. Due to urbanisation, more children will be born and raised, or migrate to live in cities. Children in cities are vulnerable to the impact of climate change due to their physiology and developmental needs. City authorities are expected to utilise their constitutional and legislative powers in climate governance to protect children from the impact of climate change. The central inquiry of this article is to explore how city-level climate law and policy protects children in the context of climate change. Using Kenya and South Africa, as key examples, it illustrates that cities have constitutional powers and legislative authority to plan, implement and govern in certain climate-related functional areas and that could be leveraged to ensure the protection of children. The discussion of cities, children's rights and climate change governance has global significance given the trends of urban growth in the present and coming decade.