Issue addressed: This study investigated the effects of food system literacy on knowledge and attitudes of food consumers. Methods: A 2-week online course critically discussed the food system through three lenses of environmental sustainability, equity and health. Participants were randomly allocated into one Control and two Intervention groups (A & B). Data collection was by online questionnaire pre- and postintervention, addressing self-perceived food system knowledge, attitudes towards food purchasing behaviours, demographic characteristics and course evaluation. Differences in knowledge and attitude scores between Control and Intervention groups were assessed. Subjects were staff and students of Flinders University in South Australia. Results: Forty-seven participants completed the course. The completion rate was 71.2%. Knowledge about the food system improved significantly for both Intervention groups when compared to the Control group (P ≤ 0.001). Although attitudes towards food purchasing behaviours also improved significantly for both Intervention groups (P < 0.001 and P = 0.005 for Interventions A and B respectively), the improvements were not significant when compared to the Control group (P = 0.065 and P = 0.43 for Interventions A and B respectively). The online methodology received positive feedback from participants. Conclusion: This 2-week online food system course showed that the pedagogy was appropriate and successful in improving self-perceived knowledge and attitudes towards food consumption. So what?: It provides encouraging indications of the potential of food system literacy to empower citizens to make healthier as well as, more environmentally and socially sustainable food choices.