Professor emeritus at McMaster University, Ronald Gillespie is one of our country's pre-eminent inorganic chemists. In the 1950s, he developed the Valence Shell Electron Pair Repulsion model to describe and predict the shapes of molecules. The model, which he continues to refine, has not only had an impact on research, but has also made molecular geometry more comprehensible to generations of students. Recognized for his teaching and mentoring skills, he has been the recipient of many awards, including the Award of Excellence in Teaching from McMaster University. He is a fellow of several learned societies, including the Royal Society of London and the Royal Society of Canada.