Merryn Tawhai, FRSNZ, is a New Zealand engineering scientist. She is a professor at the University of Auckland, deputy director of the Auckland Bioengineering Institute, where she was a fellow from 2002, and a former director of MedTech CoRE. She is known for the development of mathematical models of the lungs that will help scientists understand differences between physiologically normal lungs and the pathological changes that might occur in a disease. She was inducted into the International Academy of Medical and Biological Engineering in June 2018. In November 2018, Tawhai was elected a Fellow of the Royal Society of New Zealand.