The goal of the current study was to explore the relations between shyness, academic engagement, and academic achievement in childhood. Participants were (n = 125) children (aged 9-13 years) attending public school boards in Canada. Children completed self reports of shyness and were administered a test of nonverbal IQ. Academic achievement was assessed through both teacher ratings and standardized tests of reading comprehension and mathematics. As well, a new teacher-rated measure of academic engagement was created to assess student participation and on-task behavior in the classroom. Among the results, shyness was negatively related to teacher-rated achievement but not related to standardized test scores. Academic engagement was significantly and negatively related to shyness, and positively related to all measures of achievement. Finally, academic engagement partially mediated the relation between shyness and teacher ratings of achievement. These findings suggest that poorer teacher-rated academic performance in shy children may be partially accounted for by a lack of academic engagement in the classroom. Future studies are needed to explore "why" shy children are less likely to be engaged in the classroom. (Contains 2 footnotes, 3 tables, and 1 figure.)