INTRODUCTION: Non-prescription antibiotic dispensing is prevalent among community pharmacies in several low- and middle-income countries. We evaluated the impact of a multi-faceted intervention to address this challenge in urban community pharmacies in Indonesia. METHODS: A pre-post quasi-experimental study was carried out in Semarang city from January to August 2022 to evaluate a 7-month long intervention comprising: (1) online educational sessions for pharmacists; (2) awareness campaign targeting customers; (3) peer visits; and (4) pharmacy branding and pharmacist certification. All community pharmacies were invited to take part with consenting pharmacies assigned to the participating group and all remaining pharmacies to the non-participating group. The primary outcome (rate of non-prescription antibiotic dispensing) was measured by standardised patients displaying symptoms of upper respiratory tract infection, urinary tract infection (UTI) and seeking care for diarrhoea in a child. χ2 tests and multivariate random-effects logistic regression models were conducted. Thirty in-depth interviews were conducted with pharmacists, staff and owners as well as other relevant stakeholders to understand any persistent barriers to prescription-based dispensing of antibiotics. FINDINGS: Eighty pharmacies participated in the study. Postintervention, non-prescription antibiotics were dispensed in 133/240 (55.4%) consultations in the participating group compared with 469/570 (82.3%) in the non-participating group (p value <0.001). The pre-post difference in the non-prescription antibiotic dispensing rate in the participating group was 20.9% (76.3%-55.4%) compared with 2.3% (84.6%-82.3%) in the non-participating group (p value <0.001).Non-prescription antibiotics were less likely to be dispensed in the participating group (OR=0.19 (95% CI 0.09 to 0.43)) and more likely to be dispensed for the UTI scenario (OR=3.29 (95% CI 1.56 to 6.94)). Barriers to prescription-based antibiotic dispensing included fear of losing customers, customer demand, and no supervising pharmacist present. INTERPRETATION: Multifaceted interventions targeting community pharmacies can substantially reduce non-prescription antibiotic dispensing. Future studies to evaluate the implementation and sustainability of this intervention on a larger scale are needed.