School leadership has been recognized as one of the most influential factors in shaping teachers’ professional behavior and organizational culture. However, empirical evidence regarding the contribution of principal leadership to teachers’ work culture in elementary schools within eastern Indonesia remains limited. This study aimed to examine the effect of principal leadership on teachers’ work culture at UPTD SD Inpres RSS Oesapa, Kupang City. A quantitative survey approach was employed involving all 18 classroom teachers as research participants through a saturated sampling technique. Data were collected using Likert-scale questionnaires measuring principal leadership and teachers’ work culture. The data were analyzed using descriptive statistics and simple linear regression analysis. The findings revealed that principal leadership had a positive and statistically significant effect on teachers’ work culture. The regression analysis showed a correlation coefficient (R) of 0.995 and a coefficient of determination (R²) of 0.991, indicating that 99.1% of the variance in teachers’ work culture could be explained by principal leadership. The regression equation Y = −92.675 + 1.964X demonstrates that improvements in leadership practices contribute substantially to the strengthening of teachers’ work culture. The findings confirm that effective principal leadership plays a strategic role in fostering discipline, responsibility, collaboration, and professionalism among teachers. This study contributes empirical evidence regarding the importance of leadership practices in cultivating a positive organizational culture and improving educational quality in elementary schools