Background: Indonesian school children spend one-third of their time in school, where they are exposed to a variety of foods at school canteens. However, the healthiness of school canteens is not yet well understood. This study was conducted to (1) characterize the healthiness and quality of management of school canteens, and (2) measure readiness of school canteens to reopen following COVID-19 closures.Design and Methods: Mixed-methods were used to conduct a cross-sectional study. Data were collected from schools located in the Bantul District of Indonesia. Primary schools (n=152) were randomly selected, with a final sample size of 147. Data were collected using Google Forms, delivered via WhatsApp or email. School canteens were classified as healthy if they had a Healthy Canteen Score (HCS) >= 10, or unhealthy if they had a HCS < 10.Results: Less than half (43.5%) of school canteens were deemed to be healthy. School canteens were more likely to be healthy if the canteen manager had a formal decision letter (OR=15.2; 95% CI=3.7-62.5); used print material messaging (OR= 3.2 to 4.6 times); or received inspection by external officers periodically (OR=2.8; 95% CI= 1.04-7.5). Readiness to reopen was 4.5 (OR=4.5; 95%CI: 1.1-17.9) times higher among schools that had their own canteen, and 4 (OR=3.9; 95% CI =1.1-13.8) times higher among schools located in rural areas, adjusting for the remaining variables.Conclusions: School canteen healthiness can be improved by implementing national food policy and healthy school canteen standards accompanied by the existence of good management practices within schools, particularly following the COVID-19 pandemic.