Background and Objectives: Antimicrobial resistance (AMR) continues to emerge rapidly globally. Little evidence exists on the impact of antimicrobial stewardship programmes (ASPs) on the consumption of antibiotic across healthcare and income settings. The main objective of this review is to synthesize current evidence in this area. Methods: We searched PubMed, Web of Science, and Scopus databases from 1 Aug 2010 to 1 Aug 2020 and also additional studies from the bibliography sections of previous systematic reviews. We used the Effective Public Healthcare Panacea Project quality assessment tool to assess study quality. We measured the pooled effect of targeted ASP on antimicrobial consumption, using multi-level random effects models. The main outcome measures were proportion of patients receiving an antibiotic prescription and Defined Daily Doses per 100 patient days. Results: We identified 52 studies that measured the effect of ASPs on antimicrobial consumption. 40 studies were conducted in high income countries (HICs), and 12 in low and middle-income countries (LMICs). On average, ASPs reduced antibiotic prescriptions by 10% (95% CI [-15% to -4%]), and antibiotic consumption by 28 % (RR=0.72, 95% CI [0.56 to 0.92]). ASPs were also associated with a 79% reduction in antibiotic consumption in paediatric hospitals (95%CI [-64% to -5%] and a 28% reduction in WHO watch groups antibiotics, RR = 0.72, 95% CI [0.56 to 0.92]. Reductions were observed across all broad-spectrum antibiotic classes: fluoroquinolones (42% reduction), Penicillin/beta-lactamase inhibitor combinations (42% reduction), carbapenems (31%), macrolides (26%) and cephalosporins (15%), though these were not statistically significant. No change in penicillin consumption was identified. Conclusions: ASPs are effective in reducing antibiotic consumption in both hospital and non-hospital settings. Impact assessment of ASPs in resource-limited settings remain scarce; further research is needed on how to best achieve reductions in antibiotic use in LMICs. Keywords: antimicrobial resistance, antibiotic consumption, antimicrobial stewardship programmes