Social Anxiety (SAD) increases in prevalence as children enter adolescence. Adolescents with Autism Spectrum Disorder (ASD) are diagnosed with comorbid SAD at higher rates than these individuals are diagnosed with other clinical disorders, including depression and other anxiety disorders. However, there is little research on whether the presentation and neural underpinning of comorbid SAD within the context of ASD is the same as SAD alone. Individual and diagnostic differences exist in neural and biological mechanisms of fear conditioning. Characterization of whether neural mechanisms of fear are different within ASD with comorbid SAD and SAD alone may better inform clinical treatments. Accordingly, the present study characterizes neural responses during a fear-inducing experiment, as measured by fMRI. Fifty-seven adolescents participated in this study, with adolescents with ASD and SAD (n=17), SAD alone (n=20), and typically developing adolescents (n=20). All participants completed two fear conditioning and reversal paradigms while completing an fMRI scan. The paradigm consisted of a Social condition and Nonsocial condition. An ANOVA for fear conditioning was conducted. Results revealed significant activation in the Inferior Temporal Gyrus (ITG) during fear conditioning. No between group differences were observed, but within-group differences indicated differential modulation of the ITG in the ASD with SAD group in the Social condition compared to the Nonsocial condition. The SAD group demonstrated differential activation between conditioning stimuli in the Nonsocial condition, but not in the Social condition. Results indicate that adolescents with ASD and SAD may display different neural mechanisms for acquiring fear compared to typically developing peers. Results have potential to inform treatment approaches.