David John Hugh Cockayne FRS FInstP (19 March 1942 – 22 December 2010) was Professor in the physical examination of materials in the Department of Materials at the University of Oxford and professorial fellow at Linacre College from 2000 to 2009. He was the president of the International Federation of Societies for Microscopy from 2003 till 2007, then vice-president 2007 to 2010.