Academic achievement has become a phenomenon of interest to all, which explains why scientists have worked all out to disentangle the elements that impede student academic success. Despite the plethora of causal factors determining student academic success, this study focuses on revealing how teacher teaching performance and student learning motivation affect academic achievement in Indonesian language subjects among state junior high school students. Two survey questionnaires and the Indonesian language academic record were used to collect data from a total of 345 students, conveniently drawn from among the students enrolled at the state junior high schools in Merauke Regency, Indonesia. Obtained data were subjected to statistical analysis using simple linear regression by utilising the Statistical Package for the Social Sciences software version 21. The statistical results showed that the teacher teaching performance and student learning motivation impact significantly positively on the academic achievement in Indonesian language subjects among the state junior high school students. Teachers are crucial to the academic performance of all the students they teach and play a more dominating role in motivating children who are at risk of academic failure. Teachers are crucial to the academic performance of all the students they teach and play a more dominating role in motivating children who are at risk of academic failure and/or performing below their academic potential.
Keywords: Teaching performance, learning motivation, academic achievement, student, teacher.