Clive William Kilmister (3 January 1924 – 2 May 2010) 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. 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 (1959, King's College London, now professor emeritus of general relativity and cosmology at University of New Brunswick Fredericton ), Samuel Edgar (1977, University of London), and Tony Crilly (reader in mathematical sciences at Middlesex University).