Efforts to contain the COVID-19 virus resulted in various stay-at-home orders and school closures around the globe, causing unprecedented disruption to the lives of children and generating grave concern for their well-being. This study draws on phone interviews with 12 teachers and 6 school leaders from 13 government schools in New South Wales, Australia, to provide insight into how students fared on their return to school after the first wave of COVID-19 in 2020. The interviews highlighted negative consequences for many students including increased stress and anxiety and decreased engagement. This evidence suggests that even a comparatively short period of school closure can drive troubling changes in students' well-being and behaviour following their return to school. Given far more challenging conditions arising from the pandemic, both elsewhere in Australia and globally, we argue that attending to student well-being is as important as ensuring academic achievement and must be a key focus of policy makers and education systems moving forward.