Scientists have been predicting the severe impacts of climate change for decades, and today these threats have intensified, with climate events pushing temperatures, sea levels and biodiversity loss to record extremes. This review examines the impact of climate change on mental health in vulnerable populations residing in Africa. Medline, Embase, Ovid, APA PsycINFO, Global Health were searched for studies published after 2007 researching the psychological impact of climate change on vulnerable African populations. Studies were screened according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and results were reviewed using a narrative synthesis approach. Twenty-one articles, including 36,425 participants, were analysed. The results suggest that women, young people, farmers, migrants, people living in rural areas and survivors of climate-related traumatic experiences (such as extreme weather events) are all vulnerable to mental health impacts caused by the climate crisis. Future research is needed in African countries which have not yet been studied, including island nations. Further high-quality research is required to establish longitudinal impacts of the climate crisis and to explore the impacts on vulnerable groups which are, as yet, neglected in the research, including, e.g., ethnic minorities, indigenous groups and LGBTQ+ communities.