Intolerance of uncertainty (IU) is a dispositional characteristic wherein individuals interpret uncertainty in a negative fashion. No research has investigated the relationship between the IU subfactors, inhibitory (IU-I) and prospective (IU-P) IU, and symptoms of social anxiety disorder while utilizing a hybrid approach of symptom assessment. The current study examined the associations between IU-I and IU-P and social anxiety while utilizing a hybrid index of social anxiety, the Multidimensional Assessment of Social Anxiety (MASA). Participants (N = 684) were recruited from an outpatient psychiatric clinic. Baseline anxiety was included as a covariate for all analyses. Results found that both IU subscales were significantly associated with the MASA anhedonia and physiological arousal and avoidance subfactors. IU-I displayed specificity with the MASA functional impairment, coping with substances, and behavioral avoidance subscales. IU-P was associated with the MASA thought avoidance subfactor at trend level, whereas IU-I was not. Clinical implications and future directions are discussed.