Early childhood teachers play a critical role in supporting young children’s cognitive, social, and emotional development. Unfortunately, teachers’ abilities to promote young children’s well-being can be hindered by their own stress. Teachers can experience both workplace stressors as well as chronic stressors from adverse childhood experiences (ACEs). Very little is known about whether different sources of teacher’s stress have independent effects on their functioning. The present study examines whether workplace stress and history of ACEs are unique or redundant predictors of teacher resilience and classroom behavior, including teacher-child interaction quality, child classroom misbehavior, and staff affect regulation. Data were collected from female teachers (N = 718) across 101 childcare centers. Teachers (Mage = 39.26, SD = 13.69) completed self-report assessments on their history of ACEs, workplace stress, and resilience. (author abstract)