The Obesity and Metabolic Surgery Society of Singapore (OMSSS) is a professional organisation championing the advancement of bariatric and metabolic surgery in Singapore. It was founded in 2011 and serves to bring together surgeons, endocrinologists, dieticians, psychologists, physiotherapists and allied health professionals involved in the management of morbidly obese individuals.

The OMSSS is committed to the treatment of obese patients. It provides a platform for members to exchange knowledge on the treatment of obesity. Regular journal clubs and scientific conferences are held, with international experts in the field invited to present new surgical techniques, treatment concepts and research. The OMSSS also serves to improve awareness and medical access amongst patients with public forums and talks. A national database was established under its auspices to allow the audit of surgical outcomes and for its members to strive towards excellence. The OMSSS is also involved in reviewing national guidelines in the surgical treatment of morbid obesity.

The OMSSS is also a member of the Asia Pacific Chapter of the International Federation for the Surgery of Obesity and metabolic disorders (IFSO).