Objective: The present study aimed to understand the effectiveness of natural setting interventions to increase the level of PA in older adults ([greater than or equal to] 40 years old) with intellectual disabilities. Method: Following PRISMA's most recent guidelines, a systematic review was used to synthesise research on PA interventions implemented in a natural setting to increase PA in older adults with intellectual disabilities. Results: Eight articles were retained based on inclusion and exclusion criteria--four group and four single-case designs. Most studies showed positive but small changes in PA levels. Due to the heterogeneity of the interventions tested, the samples and PA outcomes measured as well as the quality and risk of bias of the studies, results could not be generalised. Conclusion: The systematic review highlights the pressing need for better quality research to understand if and how natural setting interventions can effectively increase PA levels in older adults with intellectual disabilities.