The aims of this systematic review were to investigate what kind of cognitive leisure activities have been used in intervention studies targeting older adults, and whether these activities improve cognitive function or inhibit cognitive decline. Based on the PRISMA declaration, we searched keywords using three electronic databases: PubMed, PsycINFO and Psy-cARTICLES. Intervention studies involving cognitive leisure activities with cognitive assessments set as outcomes were included. We regarded cognitive leisure activities as activities for enjoyment or well-being that cause intellectual stimulation (e.g. reading, playing board games). To investigate the influence of each activity on cognitive domains, multicomponent programs (e.g. combined music and art) were excluded. In total, 20 studies were included in the evaluation. Consequently, intervention studies related to arts, writing, board games, reading, handicrafts, a crossword puzzle and learning computer skills were identified. Of the 20 studies, 13 showed improvement in some cognitive domain. In 12 of these 13 studies, the intervention effects were not observed in a specific cognitive domain; rather, the intervention effects were observed across multiple cognitive domains and on working memory. The results of the present review suggest that cognitive function in older adults can be improved through cognitive leisure activity interventions. Activities related to learning new skills, that cause strong intellectual stimulation and that include communication elements were considered particularly effective tools. However, as the number of studies is small, more high-quality research needs to be accumulated.