Following the advent of plate tectonics, of which he was a pioneer, Dewey has been a leader in transforming tectonic geology to its modern form. His research is characterised by imaginative and clever model building constrained by meticulous field observation. His work on mountain belts has showed how their evolution is related to continent­continent and arc-continent collisions. He has made major contributions to understanding both the detailed nature and the timing of those events. As a frequent visitor to Australia during the last twenty years, Dewey has presented many stimulating lectures at conferences and elsewhere, and has been a lively participant in many field excursions.