<p>Informal settlements are a major concern for city authorities in the Global South, warranting the need for upgrading projects to improve upon them. Through a learning-by-comparison lens based on comparative urbanism, this study examines two upgrading projects; one in Africa (Namuwongo Upgrading and Low-Cost Housing Project, Kampala—Uganda) and another in South America (Heliópolis Project, São-Paulo—Brazil), and investigates how the former can learn from the latter. It utilizes a qualitative literature review approach to gather and analyze relevant secondary documents from Google Scholar, Scopus, and Web of Science. The findings are mobilized around the tenets of land tenure, community participation, policy formulation and implementation, planning approach to upgrading, project financing, and community rights based on comparative learning. It was found that land tenure regularization, activist-driven community engagement, critical and responsive policy frameworks, a concerted approach to housing planning and upgrading, partnership-based financing mechanisms, and the basic recognition of social rights to housing have served to make the upgrading project in São Paulo more successful than that of Kampala. The study reflects on these ‘success factors’ for São Paulo as lessons that can be learned by Kampala taking into account geographical realities that shape these cities. The study contributes to the nascent housing planning scholarly works that emphasize the need for south-south learning to improve the effectiveness of upgrading projects in Africa and the Global South more generally.</p>