Teachers' job satisfaction (TJS) can be defined as the emotional reactions of teachers to their jobs or teaching roles. In this study, it is aimed to investigate the determinants of teachers, principal and school-based factors on job satisfaction of teachers. In this study, which is based on relational survey model, secondary data obtained from TALIS-2018 evaluation were analyzed with Multilevel Structural Equation Modeling. 196 principals and 3952 teachers from Turkey who participated in TALIS-2018 survey constitute the sample of the research. According to the results of the study, teachers' age, gender, career preferences and participation in professional development activities, the locations of the schools they work in and the type of school (state/private) and the gender of the school principals were found to be determinants of job satisfaction. Teachers' work experience, having foreign students in their classes, school principal's age and work experience did not affect teachers' job satisfaction.