The connections between parents' socialization practices and beliefs about emotions, and children's emotional development have been well studied; however, teachers' impacts on children's social-emotional learning (SEL) remain widely understudied. In the present study, private preschool and Head Start teachers (N = 32) were observed using the Classroom Assessment Scoring System. Comparison groups were created based on their observed emotional support and then compared on their qualitative responses in focus group discussions on beliefs about emotions and SEL strategies. Teachers acknowledged the importance of preparing children emotionally (as well as academically) for kindergarten, but substantial differences emerged between the highly emotionally supportive and moderately emotionally supportive teachers in three areas: (1) teachers' beliefs about emotions and the value of SEL; (2) teachers' socialization behaviours and SEL strategies; and (3) teachers' perceptions of their roles as emotion socializers. Understanding such differences can facilitate the development of intervention programs and in-service training to help teachers better meet students' SEL needs.