The purpose of the study was to evaluate the relationship between school burnout, sense of school belonging, and academic achievement in medical students. This cross-sectional study was performed with students at the Ondokuz Mayıs University Medical Faculty (Samsun, Turkey) between 1 and 31 May 2019. Six hundred one (71.0%) first, second, and third-year students were included in the study. A questionnaire was employed as the data collection method. The questionnaire consisted of two parts. The first part consisted of questions investigating sociodemographic information produced by the authors by scanning the literature. The second part consisted of the School Burnout Inventory and the Psychological Sense of School Membership Scale. The relationship between the sense of school belonging, school burnout, and academic achievement was evaluated using structural equation modeling. The structural equation modeling analysis determined that school burnout played a mediating role in the relationship between the sense of school belonging and academic achievement in preclinical medical students. As the sense of belonging to the school increases in preclinical medical students, academic achievement increases. School burnout in preclinical medical students increases as a sense of school belonging decreases. Academic achievement among preclinical medical students decreases as school burnout levels increase. Increasing the sense of school belonging can be effective in preventing school burnout and increasing academic achievement.