Fearful temperament—the tendency to exhibit apprehension and/or avoidance in novel situations—is a well-established risk factor for childhood anxiety in general, and social anxiety in particular. Yet, there is little understanding of parent emotion socialization strategies that influence the association between fearful temperament and child social anxiety symptoms. The present investigation addresses this gap in the literature by examining maternal punitive responses to clinically anxious children’s negative emotions as a moderator of the covariance between fearful temperament and social anxiety symptom severity. Clinically anxious children ages 8–12 years (N = 105; 57.1% female; 61.9% racial/ethnic minority) and their mothers completed measures assessing child fearful temperament, maternal punitive emotion socialization responses, and child social anxiety symptoms. Children also participated in an anxiety-provoking speech task during which manifest social anxiety was coded by trained observers. Children’s fearful temperament coupled with greater maternal punitive responses to children’s negative emotions was associated with lower child-reported social anxiety symptoms. Models predicting manifest social anxiety were not significant. Maternal punitive responses to children’s negative emotions may encourage clinically anxious youth to approach feared situations and therefore result in lower anxiety. Yet, the potentially negative effects of punitive responses on other aspects of anxious children’s socioemotional development warrant scientific attention. Future research should examine the phenomenology of punitive parental responses among parents of anxious youth to better understand their effects on child behavior.