Brebis Bleaney CBE FRS (6 June 1915 – 4 November 2006) was a British physicist. His main area of research was the use of microwave techniques to study the magnetic properties of solids. He was head of the Clarendon Laboratory at the University of Oxford from 1957 to 1977. In 1992, Bleaney received the International Zavoisky Award "for his contribution to the theory and practice of electron paramagnetic resonance of transition ions in crystals."