Imperial College London University of East Anglia Andrew James deMello (born 1970 in Kingsbury, United Kingdom) is a British chemist and Professor of Biochemical Engineering at ETH Zürich (Swiss Federal Institute of Technology).

He was awarded an entrance scholarship to Imperial College London in 1988, subsequently obtaining a first-class bachelor's degree in Chemistry in 1991 and a PhD in Molecular Photophysics in 1995 (for research supervised by Dr. Garry Rumbles).

[1] In 1996, he was appointed as a Lecturer (Assistant Professor) in Physical Chemistry at the University of East Anglia, and in 1997 moved back to his alma mater to take up the AstraZeneca Lectureship in Analytical Sciences at Imperial College London.

In 2011, he was appointed to the Chair of Biochemical Engineering within the Department of Chemistry and Applied Biosciences at ETH Zürich,[2] and served as the Chair of the Institute for Chemical and Bioengineering from 2014 to 2016 and 2018 to 2020. deMello has made scientific contributions in diverse areas, but is best known for his work in the fields of microfluidics, nanotechnology, bioanalytical chemistry and Optical Spectroscopy, having published over 300 papers in the peer-reviewed literature.

[9] His brother is experimental physicist John deMello, who is Professor of Nanomaterials in the Department of Chemistry at Norwegian University of Science and Technology.