Aligning with the fourth objective of the WHO Comprehensive Mental Health Action Plan 2013-2030; driven towards strengthening information systems, evidence and research for mental health, this review seeks to map existing scientific (peer reviewed) evidence, identify scientific gaps and inform future research development considering the fact that published data is heterogenous, sparse and often non-existent in some African small island states. By reviewing the existing research to develop a comprehensive mapping of the available literature, this work aims to provide insights that can guide national and regional mental health policies, identity priority research areas and support evidence-informed decision making across the African SIDS. To further advance our understanding in the field of mental health and accelerate action, collaboration and data sharing between islands and institutions could positively strengthen research capacity. This can unlock further possibilities of mutual learning and knowledge sharing between African SIDS with regards to best practices in terms of uptake of local mental health research and its potential translation into appropriate services and recommended lines of actions. While the WHO targeted efforts towards doubling the output of global research on mental health by 2030 is commendable, maximising research and evidence on mental health remains an imperative priority for the African SIDS such as to guarantee that “no one is left behind” in the ongoing global mental health discourse and research initiatives.