Durward William John Cruickshank FRS (7 March 1924 – 13 July 2007), often known as D. W. J. Cruickshank, was a British crystallographer whose work transformed the precision of determining molecular structures from X-ray crystal structure analysis.

He developed the theoretical framework for anisotropic displacement parameters, also known as the thermal ellipsoid, for crystal structure determination in a series of papers published in 1956 in Acta Crystallographica.

Cruickshank subsequently studied mathematics at St John's College, Cambridge, graduating with a first-class BA in 1949, an MA in 1954 and finally a ScD in 1961.

[11] In 1991, he received the Dorothy Hodgkin Prize of the British Crystallographic Association, where he served as Vice President from 1983 to 1985.

Cruickshank died from cancer in Alderley Edge, Cheshire on 13 July 2007 at the age of 83.