Rapid urbanisation in sub-Saharan Africa poses a growing challenge to urban food security, particularly for the urban poor who face limited access to affordable, nutritious food. In this context, alternative food sources—including urban homegardens and the collection of edible wild species—hold potential to supplement diets and enhance nutritional outcomes. However, such practices are often overlooked in both policy and research, with urban farming considered marginal or non-metropolitan, and wild food collection scarcely addressed in development agendas. This study investigates the role of homegardens and wild food sources in sustaining urban livelihoods in Kampala, Uganda. A purposive sample of 96 urban and peri-urban households with homegardens was surveyed. Researchers conducted plant inventories and interviews to gather data on socio-economic status, food security, plant use, and food sourcing behaviour. Results reveal that Kampala’s homegardens are highly diverse, encompassing 73 edible plant species: 24 fruits, 22 vegetables, 14 condiments, eight roots/tubers, four legumes, and one cereal. Notably, one-third of these species are indigenous—often undervalued despite their nutritional potential. Additionally, 25% of participants reported gathering edible species within urban areas, 23% in rural settings, and 33% received food from rural relatives within the past six months. These findings underscore the critical, yet under-recognised, role of urban and peri-urban plant resources—both cultivated and wild—in supporting food and nutrition security. To foster equitable urban food systems, policy makers and planners must recognise and integrate these diverse land-use practices into urban development strategies, acknowledging their contribution to sustainable and inclusive urban food provisioning.