The term ‘cities of the Global South’ has become an increasingly popular reference in urban studies and urban development practice. Notwithstanding, the term remains underexplored and the majority of research does not address whether the Global North/Global South dichotomy is a useful theoretical framework for urban studies. This article provides a more detailed analysis of the term Global South in urban research and presents benefits and pitfalls of applying a Southern perspective. Using the research field ‘cities as transnational climate change actors’ as an example, I highlight both advantages and problems of categorising urban areas as ‘cities of the Global South’. Structural differences between Northern and Southern cities regarding climate change action do exist, and theory building on cities as transnational actors is well advised to consider those differences in order to avoid a Global North bias. However, the categories Global North/Global South are only one possibility to analyse cities as transnational climate change actors and – depending on the research question – should be accompanied by analytical attention to additional factors such as geographical location, city size or political regimes.