David A. Evans (January 11, 1941 – April 29, 2022)[1][2][3] was an American chemist who was the Abbott and James Lawrence professor of chemistry at Harvard University.

Among his best-known works is the development of aldol reaction methodology (for example, Evans' acyl oxazolidinone method).

[4][5][7] Evans began his independent research career at the University of California, Los Angeles, where he joined the faculty in 1967 and became a full professor in 1973.

[7] He was appointed the Abbott and James Lawrence Professor of Chemistry in 1990, served as chair of the Department of Chemistry and Chemical Biology from 1995 to 1998, and retired from the faculty, assuming professor emeritus status, in 2008.

[7] Although he is best known for his work on the aldol reaction, he also developed methodology for anionic oxy-Cope rearrangements, metal catalyzed hydroborations, and catalytic, enantioselective reactions based on bis-oxazoline (box) ligands.