David MacMillan is a chemist whose studies focus on organic catalysis and synthesis. David is best known for his pioneering work in the field of asymmetric organocatalysis, where the rate of a chemical reaction is increased by the presence of a chiral organic catalyst. His findings have opened up many new avenues for chemical synthesis and reaction design.

His research highlights include the discovery of a number of novel catalytic agents, including iminium ion catalysts and SOMO (singly occupied molecular orbital) and photoredox organocatalysts. He has also designed over fifty new chemical reaction processes. Alongside his research, David served as the Editor-in-Chief of the scientific journal Chemical Science.

David has received a number of awards in recognition of his work, including the Corday–Morgan Prize of the Royal Society of Chemistry in 2005 and the Ernst Schering Prize in 2015. In addition to being elected a Fellow of the Royal Society, he became a Member of the American Academy of Arts and Sciences in 2012.