ABSTRACT Objectives Antibiotic use is increasing in low- and middle-income countries (LMIC); however, few studies have examined the rates of use in a population. The use of antibiotics for liveborn infants in LMIC was examined. Design The study, a planned prospective, observational secondary analysis of the A-PLUS randomised controlled trial of azithromycin, was conducted in Global Network sites in seven countries: Bangladesh, Pakistan, India (two sites), Kenya, Zambia, the Democratic Republic of Congo and Guatemala. The analyses included liveborn infants of women planning a vaginal delivery who were enrolled in the A-PLUS trial. Methods Data were collected on liveborn infants related to non-study antibiotic use in two time-periods: (i) after delivery while in the facility, and (ii) after discharge until 42 days post-partum. Antibiotic use was also examined in preterm and term infants. The most commonly used antibiotics were classified into three groups: penicillins, cephalosporins and aminoglycosides. Antibiotics used in <1% of infants are not presented. Results Of the 29,354 eligible infants in the study, 2224 (7.6%, 95% CI 7.3–7.9) received non-study antibiotics in the facility after delivery, and 3847 (13.1%, 95% CI 12.7–13.5) received non-study antibiotics after facility discharge until Day 42. In the facility, antibiotics were given to newborns more frequently in sites in Asia and less frequently in sites in Africa and Guatemala. Similarly, after facility discharge, infants were more likely to receive antibiotics in the Asian sites and less so in the African sites and Guatemala. In the facilities, antibiotics were used predominately for prophylaxis (70.7%) but after facility discharge antibiotics were given more often for treatment (56.8%). Preterm infants received more non-study antibiotics than term infants. The antibiotics used varied substantially by time-period and site but, in general, penicillins, cephalosporins and aminoglycosides were the antibiotic categories used more frequently. Conclusions Across the Global Network sites, which represent a range of LMIC, nearly 8% of infants received non-study antibiotics more often for prophylaxis, with 13% of infants receiving non-study antibiotics following hospital discharge. With concerns about increasing antimicrobial resistance worldwide, further attention should be given to appropriate antibiotic use.