As the teaching profession becomes more demanding and teachers' work conditions become increasingly challenging, recent reports have shown declining levels of teacher well-being. Past studies on teacher well-being mostly focused its associations with teacher- and school-related outcomes. However, less research has been conducted on the implications of teacher well-being for their students' well-being. In this study, we drew on prior work on social contagion to investigate the relationship of teacher well-being with that of their students. More specifically, we examined the relationship between teacher well-being (satisfaction with the teaching profession and satisfaction with the work environment) and student well-being (life satisfaction, positive affect, and negative affect). We drew on the Programme for International Student Assessment (PISA) 2018 data which contained responses from 89,614 teachers and 93,555 students nested within 5400 schools across 19 countries/regions. Results of multilevel path analysis revealed that teacher satisfaction with the teaching profession was positively associated with student life satisfaction and positive affect, and negatively associated with negative affect. Teacher satisfaction with the work environment was positively related to student positive affect. The findings held after controlling for key covariates (school SES, and student SES and gender). Hence, teacher well-being seems to be an important contributing factor to student well-being.