School disciplinary sanctions increase sharply during adolescence, with students from certain backgrounds disproportionately affected. Strong teacher-student relationships that cultivate trust, respect and empathy may be essential to buffer against these changes. This quasi-experimental longitudinal field study trialled a brief empathic mindset intervention with teachers in English secondary schools and examined its effect on their students' (N = 1347) behaviour records and perceptions of schooling. The intervention was associated with a greater sense of school belonging and a reduction in sanctions (particularly for boys), thereby signalling the importance of making students feel heard and respected.