Penelitian ini bertujuan untuk mendeskripsikan kontribusi kompetensi guru matematika SMP terhadap prestasi belajar siswa. Kompetensi guru dikelompokkan ke dalam empat ranah, yaitu kompetensi pedagogik, profesional, sosial, dan kepribadian. Penelitian ini merupakan penelitian survei. Data penelitian dikumpulkan melalui angket, data sekunder hasil Ujian Kompetensi Guru (UKG) tahun 2015, dan nilai UAS siswa kelas VII tahun ajaran 2016/2017. Populasi penelitian adalah guru matematika SMP di Kabupaten Sleman dengan sampel penelitian sebanyak 72 guru. Sampel ditentukan dengan proportional random sampling. Untuk mengetahui hubungan antara variabel kompetensi guru dan prestasi belajar siswa digunakan analisis Partial Least Squares Structural Equation Modeling (PLS-SEM). Hasil penelitian mengungkapkan bahwa: (1) kompetensi guru dapat menjelaskan prestasi belajar siswa sebesar 44,7%; (2) terdapat kontribusi positif dan signifikan antara kompetensi pedagogik dan kompetensi profesional terhadap prestasi belajar siswa dengan nilai prediksi secara berturut-turut yaitu 0,247 (t = 1,97, p 0,05) dan 0,248 (t = 2,343, p 0,05); dan (3) kompetensi sosial dan kepribadian tidak berpengaruh signifikan terhadap prestasi belajar siswa dengan nilai prediksi secara berturut-turut yaitu 0,227 (t = 1,316, p 0,05) dan 0,070 (t = 0,410, p 0,05) Contribution of junior high school mathematics teacher competence on student’s achievementAbstractThis research aimed to describe the contribution of junior high school mathematics teacher competence to student achievement. Teacher competence was grouped into four domains, namely pedagogic, professional, social, and personality. This research was survey research. The research data was collected through a questionnaire, secondary data on the 2015 teacher competency examination results, and the seventh-grade students’ final school examination scores for the 2016/2017 academic year. The population was junior high school mathematics teachers in Sleman Regency, Indonesia, with a sample of 72 teachers. The sample was determined by proportional random sampling. To determine the relationship between teacher competence and students’ learning achievement, we used Partial Least Squares Structural Equation Modeling (PLS-SEM) analysis. The results of the study revealed that: (1) teacher competence could explain students' achievement by 44.7%; (2) there was a positive and significant contribution between pedagogic competence and professional competence on students’ achievement with a predictive value of 0.247 (t = 1.97, p 0.05) and 0.248 (t = 2.343, p 0.05), respectively; and (3) social and personality competence did not had a significant effect on student achievement with predictive values of 0.227 (t = 1.316, p 0.05) and 0.070 (t = 0.410, p 0.05), respectively.