David Millar Clark CBE FBA FMedSci (born 20 August 1954) is a British psychologist. He has been a Professor of Psychology at the University of Oxford since 2011 and is also National Clinical Adviser at the Department of Health.
His clinical research and practice has mainly focused on developing cognitive models and cognitive therapy for anxiety disorders.
Clark was instrumental, with the economist Richard Layard, in the development and implementation of the Improving Access to Psychological Therapies programme from 2003.
Clark was born in Darlington and studied experimental psychology at Oxford University. He trained as a clinical psychologist at the Institute of Psychiatry. He then returned to teach at Oxford University where he became a professor, then returned to the IOP where in 2000 he became head of psychology and founded the centre for anxiety disorders and trauma at the IOP and associated Maudsley Hospital along with fellow Oxford psychologists trauma-specialist Anke Ehlers and OCD-specialist Paul Salkovskis. Clark has won numerous awards in the UK and the USA. His research has focused on panic disorder, hypochondriasis, social phobia and posttraumatic stress disorder. Clark was strongly influenced by the American psychiatrist Aaron T. Beck who made long visits to Oxford University in the 70s and 80s, whose head of psychiatry Michael Gelder strongly believed in cognitive therapy.