Atrial fibrillation (AF) and atrial flutter (AFL) are associated with adverse outcomes in patients with heart failure and reduced ejection fraction (HFrEF). We investigated the effects of sodium-glucose cotransporter-2 inhibitors (SGLT2i) on the incidence of AF and/or AFL in HFrEF patients. PubMed and ClinicalTrials.gov were systematically searched until March 2022 for randomized controlled trials (RCTs) that enrolled patients with HFrEF. A total of six RCTs with 9467 patients were included (N= 4731 in the SGLT2i arms;N= 4736 in the placebo arms). Compared to placebo, SGLT2i treatment was associated with a significant reduction in the risk of AF [relative risk (RR) 0.62, 95% confidence interval CI 0.44–0.86;P= 0.005] and AF/AFL (RR 0.64, 95% CI 0.47–0.87;P= 0.004). Subgroup analysis showed that empagliflozin use resulted in a significant reduction in the risk of AF (RR 0.55, 95% CI 0.34–0.89;P= 0.01) and AF/AFL (RR 0.50, 95% CI 0.32–0.77;P= 0.002). By contrast, dapagliflozin use was not associated with a significant reduction in the risk of AF (RR 0.69, 95% CI 0.43–1.11;P= 0.12) or AF/AFL (RR 0.82, 95% CI 0.53–1.27;P= 0.38). Additionally, a “shorter” duration (< 1.5 years) of treatment with SGLT2i remained associated with a reduction in the risk of AF (< 1.5 years; RR 0.58, 95% CI 0.36–0.91;P= 0.02) and AF/AFL (< 1.5 years; RR 0.52, 95% CI 0.34–0.80;P= 0.003). In conclusion, SGLT2i therapy was associated with a significant reduction in the risk of AF and AF/AFL in patients with HFrEF. These results reinforce the value of using SGLT2i in this setting.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10741-022-10281-3.