Objectives Community-based social innovations (CBSIs) are one type of intervention that may help to address the complex needs of ageing populations globally. The aim of this research was to assess evidence for the effectiveness and cost-effectiveness of CBSIs involving in such contexts. Methods We conducted a systematic review of CBSIs for healthy ageing in middle- and high-income countries, including any CBSI that aimed to empower people aged 50 and over by motivating them to take initiative for their own health and wellbeing. The protocol was registered with Prospero (CRD 42016051622). A comprehensive search was conducted in 15 academic databases and advanced search in Google. We included published studies from 2000 onwards in any language. Exploratory meta-analysis was conducted for quantitative studies reporting similar outcomes, and qualitative studies were analysed using thematic analysis. Narrative synthesis was conducted. Searches yielded 13,262 unique hits, from which 44 papers met the inclusion criteria. Results Most studies reported interventions having positive impacts on participants, such as reduced depression, though the majority of studies were classified as being at medium or high risk of bias. There was no evidence on costs or cost-effectiveness and very little reporting of outcomes at an organization or system level. CBSIs have the potential for positive impacts, but with nearly half of studies coming from high-income urban settings (particularly the United Kingdom and the United States of America), there is a lack of generalizability of these findings. Conclusions Our research highlights the need to improve reporting of CBSIs as complex interventions, and for improved conceptualization of these interventions to inform research and practice.