**David Borwein** (born 1924, in Kaunas, Lithuania) is a Canadian mathematician known for his research in the summability theory of series and integrals. He has also done work in measure theory and probability theory, number theory, and approximate subgradients and coderivatives. He has recently collaborated with his son, Jonathan Borwein, and with B.A. Mares Jr. on the properties of single- and many-variable sinc integrals.

Borwein was born in 1924 in Lithuania to an of Ashkenazi Jewish family. He formerly resided and worked in St. Andrews, Scotland, before moving to London, Ontario where he eventually became Head of Mathematics at the University of Western Ontario. He was also the president of the Canadian Mathematical Society (CMS). The David Borwein Distinguished Career Award given out by the CMS is named after him. He is currently an active researcher in summability theory, classical analysis, inequalities, matrix transformations, and is professor emeritus at the University of Western Ontario, department of Mathematics. His wife of over 60 years, Bessie Borwein, is a prominent anatomist, and is professor emerita of anatomy at the University of Western Ontario.