<p>Homework adherence represents a salient, modifiable target for improving cognitive behavioral therapy (CBT) outcomes for pediatric internalizing disorders. While the adult literature has found a clear connection between CBT homework adherence and treatment outcomes, the evidence among youth have been mixed regarding the extent to which between-session homework adherence predicts CBT outcomes. The present study conducted a systematic review and meta-analysis that examines the association between homework adherence and CBT outcomes in clinical trials of internalizing disorders for youth. Fourteen studies met prespecified inclusion criteria, comprising a total sample of 1179 participants (<i>M</i> age = 11.33&#xa0;years, 53.79% female). Random-effects meta-analytic models identified a small-to-moderate association between greater homework adherence and lower post-treatment symptoms (<i>r</i> =&#xa0;-0.23, <i>p</i> &lt; 0.001). Interestingly, disorder type significantly moderated this association, such that the association between homework adherence and CBT outcomes was strongest in obsessive–compulsive disorder (OCD) samples (<i>r</i> =&#xa0;-0.42), compared to anxiety (<i>r</i> =&#xa0;-0.14) and depression (<i>r</i> =&#xa0;-0.06). Findings underscore the importance of homework adherence as a mechanism of youth CBT, particularly for OCD. Enhancing homework adherence may help optimize CBT outcomes in pediatric populations.</p>