Research Findings: This study is an examination of (a) links between preschool children's temperament (effortful control, shyness, and anger) and teacher-child conflict and (b) classroom instructional and emotional support as moderators of associations between temperament and teacher-child conflict. Children (N = 104) were enrolled in 23 classrooms in 9 preschools in a midwestern city. Teachers provided ratings of children's temperament and parents reported demographic information in the fall of the school year, classrooms were observed in the winter to assess instructional and emotional support, and teachers rated conflict with children in the spring. Multilevel models were estimated, and 3 main findings emerged. First, children's effortful control was negatively associated with their level of conflict with teachers. Second, children's effortful control was negatively related to teacher-child conflict in classrooms with low emotional support but unrelated to conflict in classrooms with high emotional support. Third, children's effortful control was negatively related to conflict in classrooms with high instructional support but unrelated to conflict in classrooms with low instructional support. Practice or Policy: Findings highlight the importance of considering the interplay of children's effortful control and preschool classroom instructional and emotional support in the development of early teacher-child conflict.