This study examined the influence of learner-centered and teacher-centered instruction on student interest and academic achievement in English and mathematics. To accomplish this, multiple regression analysis with the fixed effects model was used based on data from the Busan Educational Longitudinal Study (BELS). The results indicated that learner-centered instruction had a more positive impact on student interest compared with teacher-centered instruction. However, learner-centered instruction negatively influenced student academic achievement, whereas teacher-centered instruction did not impact academic achievement. These findings suggest that educational policy needs to be directed toward improving teaching methods for students’ cognitive and affective learning outcomes.