This study was conducted to determine the relationship and the effect of school leaders' authentic leadership towards teachers' job stress. A cross-sectional quantitative approach using a questionnaire has been used on 330 teachers from 143 excellent performance primary schools in the Eastern part of Peninsular Malaysia. Authentic Leadership Questionnaire instrument (ALQ) was adopted from Walumbwa et al., (2008) and Teachers' Work Stress instrument (TWS) by Collie et al. (2012) and Boyle, Borg, Falzon, & Jr. (1995) was used to obtain the data. Descriptive statistical analysis shows that the level of authentic leadership among the leaders is high and the level of teachers' job stress is. The finding also revealed that there is a moderate negative significant relationship between school leaders' authentic leadership and teachers' job stress. Furthermore, Stepwise's multiple regression analysis shows that authentic leadership also contributed a significant negative impact on teachers' job stress. This study recommends that school leaders adopt authentic leadership in their practices to improve and manage teachers' job stress which in turn will help to improve school excellence, especially across the current era of globalization.