Although decades of research have examined relationships between social anxiety and negative outcomes, this study examined relations with indices of positive psychological functioning. In college students (n = 204), a factor analysis on self-report measures of positive psychological functioning derived 3 conceptually meaningful broad domains: Positive Subjective Experiences, Curiosity, and Appetitive Motivations. Analyses were conducted to test whether social interaction anxiety demonstrated unique relationships with positive psychological domains after controlling for shared variance with social observation anxiety (e.g., eating in public, public speaking) and neuroticism. Social interaction anxiety explained unique variance in all 3 domains after separately controlling for social observation anxiety and neuroticism. In contrast, social observation anxiety demonstrated near-zero relationships with all 3 domains, and neuroticism predicted Positive Subjective Experiences, and to a lesser degree, Curiosity. These data provide evidence for the unique association between social interaction anxiety and positive psychological functioning, with implications for future basic and applied research.