Penelitian ini bertujuan untuk untuk mendeskripsikan pengaruh keterlibatan orang tua, perilaku guru, dan motivasi belajar baik terhadap prestasi belajar mata pelajaran matematika siswa kelas X SMA. Penelitian ini merupakan penelitian expost facto. Populasi dalam penelitian ini adalah siswa kelas X MIPA SMA Negeri 4 Yogyakarta, Indonesia, tahun ajaran 2016/2017. Sampel penelitian sejumlah 121 siswa ditentukan menggunakan simple random sampling technique. Pengumpulan data menggunakan studi dokumen hasil belajar matematika siswa dan angket yang telah dibuktikan validitas serta diestimasi reliabilitasnya. Teknik analisis data yang digunakan adalah analisis regresi ganda. Hasil penelitian menunjukkan bahwa: (1) terdapat pengaruh positif dan signifikan masing-masing variabel yaitu keterlibatan orang tua, perilaku guru, motivasi belajar terhadap prestasi belajar matematika siswa kelas X SMA Negeri 4 Yogyakarta; dan (2) secara bersamaan (simultan) variabel keterlibatan orang tua, perilaku guru, dan motivasi belajar berpengaruh positif dan signifikan terhadap prestasi belajar matematika siswa kelas X SMA Negeri 4 Yogyakarta.The effect of parental involvement, teacher behavior and learning motivation on students’ mathematics achievementAbstractThis research aimed to describe the effect of parental involvement, teacher behavior, learning motivation on students’ mathematics achievement in grade X of Junior High School. This research was ex post facto research. The population was grade X students of SMA Negeri 4 Yogyakarta, Indonesia in the 2016/2017 academic year. The sample of 121 students was established using the simple random sampling technique. The data were collected through documents study of students’ mathematics achievement results and using a questionnaire that had been proven its validity and estimated its reliability. The data analysis technique used is linear and multiple regression. The research finding shows that (1) there is a positive and significant effect of each variable namely parental involvement, teacher behavior, learning motivation on mathematics achievement of grade X students of SMA Negeri 4 Yogyakarta; and (2) parental involvement, teacher behavior, and learning motivation simultaneously provide a positive and significant effect on mathematics achievement of grade X students of SMA Negeri 4 Yogyakarta.