Concerns about physical appearance are a salient feature of several psychiatric conditions, and various self-report-based measures of appearance concerns have been developed for different disorders. An important question, with implications for understanding comorbidity and processes underlying it, is whether these different measures may in fact be indexing a common construct. Using confirmatory factor analysis (CFA) in a large mixed-sex undergraduate sample (N = 704), the current study found evidence for a higher-order factor accounting for substantial shared variance in measures of appearance concerns devised for use with eating disorders, social anxiety disorder, and body dysmorphic disorder. Hierarchical mediation analyses revealed that this general factor accounted for much of the variance shared between each appearance concerns measure and scale-assessed symptoms of its affiliated disorder. Additionally, the general appearance concerns factor accounted for most of the variance in a shared disorder factor representing the comorbidity among eating, social anxiety, and body dysmorphic symptoms. Collectively, these findings suggest that appearance concerns are general and transdiagnostic rather than disorder specific and may contribute to the systematic comorbidity evident among appearance-related psychopathologies.