Food insecurity is a threat to children's development and in Australia 13.5% of households experience food insecurity. Universal school food programs, however, are not provided nationally. Teachers and not‐for‐profit organisations have instead mobilised to tackle hunger. The strategies used and their effects on students have limited empirical evidence. The aim of this study is to gain perspectives on the causes and consequences of children's food insecurity in schools and describe food security strategies adopted. One hundred schools in Victoria, which participate in a not‐for‐profit lunch program provided by Eat Up were invited to take part in the study. Fifteen staff (including school principals and welfare officers) from 15 schools were recruited for semi‐structured interviews. There was evidence that children experience adverse quantity, quality, social and psychological impacts of food insecurity whilst in school settings. Participants described employing multiple strategies including free meals (e.g. lunch, breakfast) and food (e.g. parcels) for food insecure students and their families. In our sample, multiple strategies were being employed by schools to reduce food insecurity, but there remains unmet need for additional wide‐scale initiatives to address this critical issue and its causes and consequences.