Background: Converging evidence points to the relevance of adolescent wellbeing as a resource for positive development and successful learning. As schools represent one of the most significant environments for adolescent development, there is increasing interest in students' wellbeing in schools. However, the growing body of research reveals great heterogeneity regarding operationalisations of school-related wellbeing. Purpose: The present study aims to contribute to the conceptualisation of the construct by taking a closer look at experiences within the context. In doing so, it takes a multi-informant approach and explores students' and teachers' perspectives. Method: A survey was conducted among secondary school students (n = 150) and teachers (n = 197). Participants provided responses to open-ended questions, addressing their general understanding of the construct and indicators of high and low levels of school-related wellbeing. Data were analysed using a qualitative content analysis approach. The EPOCH model of Kern et al., with the dimensions "Engagement," "Perseverance," "Optimism," "Connectedness" and "Happiness," was applied as a categorisation framework. For coded segments that did not correspond to the EPOCH domains, the category system was expanded inductively. Findings: Just over three quarters of all coded segments referred to the EPOCH domains. Three categories were inductively added: "Physical health," "Achievement" and "Framework conditions." Overall, in terms of the content addressed as well as frequencies of the themes, there was a degree of homogeneity across the responses of students and teachers, although findings suggested greater emphasis on eudaimonic aspects in the teacher sample. Conclusions: The present study provides initial insights into students' and teachers' perspectives regarding the conceptualisation of school-related wellbeing and supports the approach of conceptualising it both in terms of hedonic and eudaimonic aspects. It supports the application of the EPOCH model to the school context, considers additional detailed aspects and underscores the multidimensionality of the construct. Future research is required to investigate the roles of all identified categories and whether they correspond to a statistical measurement model.