A/Prof Marion Aw is a Senior Consultant in the Division of Paediatric Gastroenterology, Nutrition, Hepatology and Liver Transplantation, and the Paediatric Liver Transplantation Programme, National University Centre for Organ Transplantation at National University Hospital (NUH). She is also an Associate Professor at the Yong Loo Lin School of Medicine, National University of Singapore (NUS).

She graduated from NUS and received her post-graduate paediatric training at NUH. After completing her paediatric specialist training in Singapore, she spent 2 years with the Paediatric Liver Unit at King's College Hospital, London, United Kingdom. Her MD thesis (University of London) is based on clinical and research work done whilst she was there. In 2004, she was elected to Fellowship of the Royal College of Paediatrics and Child Health, United Kingdom.

A/Prof Aw’s area of clinical expertise is in paediatric gastrointestinal disease, hepatology and liver transplantation. She is a member of the National Liver Transplant Programme. A/Prof Aw also has an interest in nutrition and feeding issues in children. This led her to start the Interdisciplinary Feeding and Nutrition Clinic at NUH in 2013. In 2017, she set up the Paediatric Inflammatory Bowel Disease Regional Network and is the Chair of its EXCO.

In addition to clinical practice, A/Prof Aw is also passionate about teaching and training medical undergraduates and post-graduate paediatric doctors. She was previously the program director for paediatric residency training at NUH and Assistant Dean (Education) of NUS Yong Loo Lin School of Medicine. She is currently the Education Director at NUH, and the Vice Dean (Students) of NUS Yong Loo Lin School of Medicine.