Psychological co-morbidities common in polycystic ovary syndrome (PCOS) may contribute to disordered eating and subsequent weight gain. This cross-sectional study aimed to determine the prevalence of disordered eating and a range of eating disorders and demographic risk factors associated with these behaviours within an Australian group of women with and without PCOS. Data from 899 women with ( = 501) and without ( = 398) PCOS were analysed as possibly indicative of disordered eating or eating disorders using the Eating Disorder Examination Questionnaire (EDE-Q) and The Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria. Disordered eating ( = 0.012) but not eating disorders ( = 0.076) were more prevalent in women with PCOS compared to controls. Increased body mass index (BMI) [Odds Ratio (OR): 1.03; 95%; Confidence Interval (CI): 1.01, 1.05, = 0.012] and older age [OR: 1.05; 95%CI: 1.02, 1.08, = 0.002] but not PCOS diagnosis [OR: 1.43; 95%CI: 0.96, 2.13 = 0.078] increased the odds of disordered eating. Increased BMI [OR: 1.04; 95%CI: 1.02, 1.06, < 0.001] and younger age [OR: -0.95; 95%CI: 0.93-0.95, < 0.001] but not PCOS diagnosis [OR: 1.38; 95%CI: 0.97, 1.95, = 0.076] increased the odds of an eating disorder. Clinicians are recommended to screen all women with PCOS for possible disordered eating behaviours, with particular attention to women with elevated BMI.