Introduction: Physical activity (PA) is important for older people to maintain functional independence and healthy ageing. PA interventions for community-dwelling older adults are often delivered by healthcare professionals, fitness instructors or trained members of a research team. Innovative approaches are needed to ensure that these interventions are practical and sustainable.This systematic review explores the effectiveness of volunteer-led PA interventions in improving health outcomes for community-dwelling older people. Methods: Following PRISMA recommendations, five databases (MEDLINE, Embase, CINAHL, PEDro, Cochrane library) were systematically searched until May 2019, for studies using trained volunteers to deliver PA interventions for community-dwelling older people aged ≥ 65 years, reporting on participant outcomes. Meta-analysis was not conducted due to included study heterogeneity. Results: Twelve papers (eight studies including three randomised controlled trials (RCTs)) were included in the review; five papers reported different outcomes from the same RCT. Intervention settings included community exercise groups (n=4), home (n=2) and care homes (n=2). All eight studies included strength and balance exercises and frequency of PA ranged from once daily to weekly sessions. The three RCTs showed improvement in grip strength, nutritional and frailty status, and reduction in fear of falling, among 39 older adults (mean age 83 years) who received a physical training and nutritional intervention; improvement in grip strength and activity of daily living scores among 56 nursing home older adults (mean age 78 years) who received resistance exercise training; and a significantly higher proportion of older adults (n = 193, 9% improvement vs 0.5% in the control group) achieved the recommended target of 150 minutes of moderate vigorous PA per week using the Falls Management Exercise intervention. Two studies compared volunteer and health professional-delivered PA interventions and reported that both interventions were equally effective in reducing fear of falls and improving quality of life. Two quasi-experimental studies reported improvement in functional outcomes including functional reach, timed up and go test, and chair stand. A large prospective cohort study (n = 1620) reported a reduction in disability among older adults who received volunteer-led exercise compared to control, with a hazard ratio of 0.73 (95% CI 0.62-0.86) for development of disability. Conclusions: Trained volunteers can lead PA interventions among community-dwelling older adults with some evidence of improved health outcomes including nutritional, functional and frailty status. [ABSTRACT FROM AUTHOR]