While some mental disorders are inherently characterized by a disconnect from reality, sufferers of most disorders experience varying degrees of clinical insight—the degree to which someone with a mental illness understands that they are afflicted with a mental disorder and that their symptoms are caused by this psychopathology. Although clinical insight in OCD is thought to play an especially important role in determining various clinical characteristics and treatment outcomes, insight has not been addressed from a comprehensive developmental framework, the importance of which this review will elucidate. Findings from this review suggest that clinical insight is typically associated with more complex cases and worse treatment outcomes in children and adults, but also reveals that there are nuances between pediatric and adult OCD cases with low insight. Implications of these findings, future research directions, and recommendations for the field are discussed.