This study investigated the relation between teachers’ occupational well-being and the quality of teacher–student interactions in lower secondary schools in Finland. Teachers (N = 48) self-rated their occupational well-being in terms of engagement, stress, job demands, and emotional exhaustion. Teacher–student interactions in classrooms were video-recorded and coded with the Classroom Assessment Scoring System. The results of multivariate regression analyses showed that teachers who reported higher work-related stress were observed with a lower quality of emotional support, classroom organization, and instructional support when controlling for background factors. It is proposed that the observed quality of teacher–student interactions is related to teachers’ work-related stress in lower secondary schools.