Objective This systematic review and meta‐analysis aimed to examine the effects of repetitive transcranial magnetic stimulation (rTMS) on cognitive function in older patients with cognitive impairment. Methods A literature search was performed for articles published in English using the 10 databases (MEDLINE, EMBASE, PsycINFO, INSPEC, the Cumulative Index to Nursing and Allied Health Literature Plus, AMED, Biological Sciences, ClinicalTrials.gov, the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews) from their inception to May 2016. The primary outcome was cognitive function as measured by the Mini‐Mental State Examination or the Alzheimer's Disease Assessment Scale‐cognitive subscale. Results Seven RCTs were included in the meta‐analysis, with a sample of 107 active and 87 sham rTMS. Active rTMS was found to be more effective in improving cognition (Hedges' g = 0.48; 95% confidence interval 0.12 to 0.84). Conclusions High‐frequency rTMS showed a benefit on cognition amongst older patients with mild to moderate Alzheimer's disease. rTMS was shown to have great potential as a safe and well‐tolerated alternative intervention for cognition. Copyright © 2017 John Wiley & Sons, Ltd.