In recent years, student well-being is increasingly on the research agenda. Yet, little is known about the well-being of students with autism spectrum disorder (ASD). The current study used semi-structured interviews and sought the views of 20 high school teachers of students with ASD to investigate the concept of well-being for this group of students. Grounded theory approaches were used to analyse the data. Teachers conceptualised well-being as consisting of three domains (i.e., peer relationships, sense of safety, engagement), identified three categories of barriers (i.e., teacher's ability to effectively teach students with ASD, impact of ASD, environment), and several external and internal assets of well-being. Discussion on recommended practices for schools to enhance the well-being of students with ASD are provided.