Peter Brian Herrenden Birks QC FBA (3 October 1941 – 6 July 2004) was the Regius Professor of Civil Law at the University of Oxford from 1989 until his death. He also became a Fellow of the British Academy in 1989, and an honorary Queen's counsel in 1995. He was a Fellow of All Souls College, Oxford. He is widely credited as having sparked academic enthusiasm for the English law of Restitution, and is often considered to have been one of the greatest English legal scholars of the 20th century.