First, we define the concepts of well-being and happiness at school. Then, we explore well-being at school from the perspective of the teacher-student relationship, both from the point of view of the students and of the teachers. To do this, the main results of two studies carried out in 2019 and 2020, mainly in Quebec, are presented. Finally, the two perspectives, that of the pupils and that of the teachers, are confronted. The results of our analysis highlight the importance of (...) the teacher-student relationship both in the student's school experience and in the teacher's professional practice. The affective nature of the relationship seems to occupy a major place. Suggestions and recommendations for optimizing the quality of the teacher-student relationship, for the happiness of learning or teaching, are proposed. (shrink)