Falls are common in older adults with psychiatric disorders, but the epidemiological findings have been inconsistent. This meta-analysis examined the prevalence of falls in older psychiatric patients and its moderating factors. PubMed, EMBASE, Web of Science and PsycINFO databases were independently searched by three investigators from their inception date to Nov 31, 2017. The random effects meta-analysis was used to synthesize the prevalence of falls, while meta-regression and subgroup analyses were conducted to explore the moderating factors. Sixteen of the 2061 potentially relevant papers met the entry criteria for the meta-analysis. The pooled lifetime prevalence of falls was 17.25% (95% confidence interval: 13.14%–21.35%). Neither univariate and nor multivariate meta-regression analyses revealed any moderating effects of the study region, duration, sample size, and quality on the prevalence of falls (P values > 0.05). Falls in older adults with psychiatric disorders are common.