This qualitative research aims to examine the opinions of school administrators, teachers, and middle school students about what makes a good mathematics teacher. Interviews were conducted with thirty-five participants: ten school administrators, ten mathematics teachers, and fifteen middle school students. A semi-structured interview form consisting of three questions was used. According to the results obtained, students, teachers, and school administrators agreed that a good mathematics teacher should know how to teach mathematics. The students assessed a good mathematics teacher as someone who not only explains mathematics well, but also takes into account the positive teacher-student relationship. They also expressed that they learn better when the mathematics teacher teaches mathematics by relating it to real life and prepares concrete examples like pictures and graphics. Mathematics teachers defined a good mathematics teacher in terms of knowledge of mathematics, knowledge of mathematics teaching methods, and affective features. According to school administrators, on the other hand, a good mathematics teacher should have mathematics teaching ability; develop himself/herself professionally; communicate with students, colleagues and parents effectively; and obey the rules of institution.