David J. Lary (born 7 December 1965) is a British-American atmospheric scientist interested in applying computational and information systems to facilitate discovery and decision support in Earth system science. His main contributions have been to highlight the role of carbonaceous aerosols in atmospheric chemistry, heterogeneous bromine reactions, and to employ for , and the use of machine learning for remote sensing applications. He is author of AutoChem, that constitutes an automatic computer code generator and for chemically reactive systems. It was designed primarily for modeling atmospheric chemistry, and in particular, for chemical data assimilation. He is author of more than 150 publications receiving more than 3,850 citations.