This study attempts to describe and analyze the direct and indirect effects of Achievement Motivation as an intermediary variable in the correlation between the Principal's Transformational Leadership, Work Ethic, and teacher performance. The population of 203 junior high school teachers in Balangan Regency is sampled using proportionate random sampling to get a sample of 176 individuals. This research analysis employed descriptive and inferential SPSS 22 statistics. Using a questionnaire, information was gathered about Transformational Leadership of Principals (48 items), Work Ethics (35 items), Motivation for Achievement (30 items), and Teacher Performance (26 things). (1) The principal's transformational leadership, the teacher's work ethic, the teacher's success motivation, and the teacher's performance all fall into the "high" category, as indicated by the study's findings. The principal transformational leadership has a direct impact on teacher work ethic, teacher achievement motivation, and teacher performance. (3) There is an indirect effect of the principal's transformational leadership, teacher work ethic, and teacher achievement motivation on teacher performance.