This study investigated the role of children's emotion regulation skills and academic success in kindergarten, using a sample of 325 five-year-old children. A mediational analysis addressed the potential mechanisms through which emotion regulation relates to children's early academic success. Results indicated that emotion regulation was positively associated with teacher reports of children's academic success and productivity in the classroom and standardized early literacy and math achievement scores. Contrary to predictions, child behavior problems and the quality of the student teacher relationship did not mediate these relations. However, emotion regulation and the quality of the student-teacher relationship uniquely predicted academic outcomes even after accounting for IQ. Findings are discussed in terms of how emotion regulation skills facilitate children's development of a positive student-teacher relationship and cognitive processing and independent learning behavior, both of which are important for academic motivation and success.