Background <p>Internalizing disorders are the most common psychiatric disorders in youth and are associated with a host of deleterious outcomes (e.g., self-harm, substance use, interpersonal difficulties), highlighting the critical need for identifying risk factors that confer risk for these disorders. The present study investigated the unique and shared roles of two prominent cognitive biases—anxiety sensitivity and interpretation biases—as predictors of internalizing symptom severity in clinically anxious youth, above and beyond the effects of negative emotionality and after accounting for sociodemographic covariates.</p> Method <p>A diverse sample of clinically anxious youth (<i>N</i> = 105; M_age = 10.09&#xa0;years, SD = 1.22; 56.7% female; 49% ethnic minority) completed a diagnostic interview and self-report measures of interpretation biases, anxiety sensitivity, and internalizing symptom severity.</p> Results <p>Hierarchical regression analyses revealed that both anxiety sensitivity (<i>b</i> = 0.77, 95% CI [0.53, 1.00], <i>sr</i>^<i>2</i> = 0.11) and interpretation biases (<i>b</i> = 0.21, 95% CI [0.11, 0.30], <i>sr</i>^<i>2</i> = 0.05) accounted for an additional 22% of unique variance in internalizing symptom severity (<i>p</i> &lt;.001), above and beyond the effects of negative emotionality. Post hoc exploratory analyses identified the disease and social concerns facets of anxiety sensitivity, and the overgeneralization facet of interpretation biases, as predictors of internalizing symptoms.</p> Conclusion <p>Future research should examine whether targeting cognitive biases would be beneficial among temperamentally labile youth.</p>