Background: The role of teachers in nurturing students' sense of belonging cannot be overemphasised. Students who do not feel accepted by their teachers are at risk of withdrawing from school life and feeling disaffected. This study contributes to theories on school belonging by investigating the contribution of teachers to students' sense of school belonging, the association of students' attitudes towards teachers, and their sense of school belonging with students' mathematics achievement. Aim: To provide empirical evidence of how students' attitudes towards teachers contributed to their sense of school belonging, as well as their mathematics achievement. Setting: A representative sample of 10932 grade 5 students at 297 schools in South Africa completed a contextual questionnaire and a mathematics assessment during the 2015 Trends in International Mathematics and Science Study (TIMSS). Methods: The TIMSS 2015 data were used to develop indicators of students' attitudes towards teachers, sense of school belonging and home socio-economic status. Absenteeism and the extent of bullying were also considered. Descriptive and inferential statistical analyses were performed. Results: A high positive correlation between students' attitudes towards teachers and their sense of school belonging was found. Students' attitudes towards teachers and their sense of belonging contributed significantly to mathematics achievement. Conclusion: The study confirms the crucial role that a sound student-teacher relationship plays in a healthy sense of school belonging and in terms of academic performance. The school environment should be managed in a manner that allows for mentoring relationships between students and teachers to be strengthened.