Objective: Due to limited efficacy of medications, non-pharmacological interventions (NPI) are frequently co-administered to people with moderate to severe dementia (PWMSD). This systematic review and meta-analysis investigated the effects of NPI on activities of daily living (ADL), behavioral and psychological symptoms of dementia (BPSD), and cognition and quality of life (QoL) of PWMSD. Methods: A literature search was conducted in the following databases: Cochrane CENTRAL, EMBASE, Medline, CIHNAL, PsycINFO, KoreaMED, KMbase, and KISS. We conducted a meta-analysis on randomized controlled trials and used the generic inverse variance method with a fixed-effects model to calculate the standardized mean difference (SMD). The protocol had been registered (CRD42017058020). Results: Ten randomized controlled trials met the inclusion criteria of the current meta-analysis. NPI were effective in improving ADL [SMD=0.28, 95% confidence interval (CI)=0.11–0.45] and reducing depression (SMD=-0.44, 95% CI=-0.70– -0.19). However, NPI were not effective in reducing agitation, anxiety, or overall, or improving cognitive function. In a subgroup analysis, music therapy was effective in reducing overall BPSD (SMD=-0.52, 95% CI=-0.90– -0.13). Conclusion: Albeit the number of studies was limited, NPI improved ADL and depression in PWMSD.