OBJECTIVE: Psychiatric comorbid conditions are common among individuals with Eating Disorders (EDs), and these symptoms may exacerbate and/or interact with ED symptoms and impact treatment effectiveness. Whilst comorbid symptomology in Anorexia Nervosa (AN) has been well described, less is known about how the 'newer' ED diagnoses of Atypical Anorexia Nervosa (AAN) and Avoidant/Restrictive Food Intake Disorder (ARFID) differ relative to AN. The current study aimed to extend the literature by examining similarities and differences in comorbid symptomology AN, AAN, and ARFID groups. METHOD: In this cross-sectional study, young people (n = 311, female = 87.8%, mean age = 14.32: SD = 2.05, range 5-17) with AN, AAN, and ARFID completed self-report measures capturing comorbid symptomology prior to engaging in treatment at a specialist ED outpatient clinic. RESULTS: There was no difference between AN and AAN on any measure of comorbid symptoms. Both showed severe levels of comorbidity with over half exceeding the cut-point for four or more comorbid diagnoses, with Obsessive Compulsive Disorder, depression and Social Anxiety particularly common. ARFID, on the other hand, had comparatively less severe comorbid symptoms compared to AN and AAN. CONCLUSIONS: Findings provide a better understanding of the nature of comorbid symptomology among these disorders and encourages future research to investigate the role that they play in the treatment outcome.