The mental health and wellbeing of young people is increasingly a concern in schools. This study explores how English secondary school teachers perceive and engage with the concept of wellbeing. By asking teachers to reflect on their practice, we can draw out their relational experience and knowledge about wellbeing in the classroom. Twenty teachers were interviewed about their practice in the context of the COVID-19 pandemic and during the academic year 2020-21. Reflexive thematic analysis reveals the challenges experienced by teachers. Specifically, we find a perceived role conflict for teachers between giving care and purveying knowledge. We draw on recent policy research and the work of Nel Noddings to account for this conflict in terms of conceptualisations of teaching practice and purpose. We illustrate how an emphasis within schools on 'doing well' academically undermines and marginalises a more holistic sense of 'being well', which contributes to a set of strains on teachers personally, professionally and relationally in terms of their interactions with students and colleagues. We propose that 'doing well' arises out of 'being well', rather than the converse, and should hence be an educational policy priority. Finally, we offer implications for how wellbeing may be woven into school culture.