Clive William Kilmister was a British mathematician who specialised in the mathematical foundations of physics, especially quantum mechanics and relativity.
Kilmister attended Queen Mary College London for both his under- and postgraduate degrees. Whilst an undergraduate he was friends with Frank W. J. Olver. In a 1988 Gresham Coillege lecture, he recounted how the two of them would shout requests to formulas to one another in order to prepare for their final exams. Kilmister regarded Olver as a better mathematician than himself, but suggests that had Olver not caught a bout of flu, then Olver would surely of one the schjolarship which launched Kilmister's subsequent career. His 1950 PhD on The Use of Quaternions in Wave-Tensor Calculus related to Arthur Eddington's work, and was supervised by cosmologist George C. McVittie, who was one of Eddington's students. His own students included Brian Tupper, Samuel Edgar, and Tony Crilly.
Kilmister was elected as a member of the London Mathematical Society during his doctoral studies. Upon graduation, he began his career as an Assistant Lecturer in the Mathematics Department of King's College in 1950.