William Reginald Dean (1896–1973) was a British applied mathematician and fluid dynamicist.
Dean carried out pioneering work in the study of fluid flow at low Reynolds numbers, by applying methods from elasticity theory.
[1] Dean was an undergraduate at Trinity College, Cambridge.
During the war he undertook mathematical work as part of the Anti-Aircraft Experimental Section of M.I.D.
[2] He also held the Goldsmid Chair in Applied Mathematics at University College London (from which he retired in 1964),[3] and a chair at the University of Arizona.