Background: The prevalence of obstructive sleep apnoea (OSA) is increasing worldwide. Bariatric surgery is an option where conventional measures to achieve weight loss fail. We compared peri-operative outcomes in patients living with obesity with and without OSA undergoing bariatric surgery. Methods: Retrospective cohort study of consecutive patients undergoing bariatric surgery at a tertiary referral centre. Data were extracted from electronic patient records. Primary outcomes were the rate of peri-operative complications and level of respiratory support. Secondary outcomes were length of stay (LOS), and the highest level of care required. Results: 302 patients underwent surgery (age 47 (±11.6) years, 238 (78.8%) female, body mass index (BMI) 48.1 (±7.8) kg/m2). 101 (33.4%) of patients had moderate or severe OSA, or mild OSA with significant sleepiness, and were prescribed continuous positive airway pressure (CPAP), whilst 201 (66.6%) had mild OSA without symptoms or no OSA and weren?t. Patients requiring CPAP were more obese (BMI 50.2 vs 47.0 kg/m2, p<0.001).  Complications were analysed individually and according to the Clavien-Dindo classification. The incidence of each individual complication did not differ between groups. When grouped into Clavien-Dindo grades, only grade I complications differed: CPAP 9% vs non-CPAP 2.6%, p =0.03). LOS was longer in the CPAP group (3 [1.5] vs 2 [1] days p=0.002). Conclusion: The rate of peri-operative complications in patient with OSA undergoing bariatric surgery is low and can be addressed by the provision of CPAP therapy in most cases. A longer LOS and more frequent grade I complications requires selection of appropriate monitoring.