Despite relatively universal feelings of discomfort in social situations, there is considerable evidence for diversity in the social behaviors and peer experiences of socially anxious youth. However, to date, very little research has been conducted with the aim of identifying factors that differentiate socially anxious youth who are more socially competent from those who are less socially competent. The present study addresses this gap in the literature by examining whether physiological and cognitive coping responses to social stress moderate the association between social anxiety and social competence. Participants were a community sample of 123 fifth and sixth graders (Mage = 12.03). Social anxiety was measured globally and in the context of a lab-based peer evaluation situation, and social competence was assessed via teacher-reports. Physiological (i.e., skin conductance level reactivity, SCLR, and respiratory sinus arrhythmia reactivity, RSAR) and coping (i.e., disengaged) responses to social stressors were also assessed. Results indicated that SCLR and disengaged coping with peer victimization moderated associations linking global and context-specific social anxiety with social competence, such that social anxiety was associated with lower social competence at lower levels of SCLR and higher levels of disengaged coping with peer victimization. Thus, whether socially anxious preadolescents exhibit more or less competent social behavior may depend, in part, on how they respond to peer-evaluative stress. Inflexible physiological responses and disengaged coping responses may undermine social competence, whereas engaged responses may counteract socially anxious preadolescents’ tendency to withdraw from social interactions or focus primarily on threat cues.