Objective: This study examined the associations between insomnia, anxiety, and depression in college women with eating disorders (EDs). Participants: Six hundred and ninety women from 28 US colleges who screened positive for an ED were assessed for psychiatric comorbidities. Women were, on average, 22.12 years old, mostly White (60.1%) and undergraduates (74.3%). Methods: Two mediation models were tested to determine if depression and/or anxiety mediated the relationship between insomnia and ED symptomatology. Results: One-fifth of the sample (21.7%) reported clinically moderate and severe levels of insomnia. Both depression (B = 0.13, p < 0.001) and anxiety (B = 0.13, p < 0.001) significantly mediated the relationship between insomnia and ED psychopathology. Conclusions: Insomnia is relatively common in college-age women with EDs. Findings suggest that this association between ED and sleep disturbances can be explained, in part, by changes in depression and anxiety. Clinicians should consider incorporating mental health assessments for insomnia, depression, and anxiety into current ED prevention, intervention, and screening efforts on college campuses.