Stephen William Hawking, CH (Order of the Companions of Honour), CBE (Order of the British Empire), FRS (Fellow of the Royal Society), FRSA (Royal Society for the encouragement of Arts, Manufactures & Commerce) (born 8 January 1942) is a British theoretical physicist (theoretical physics), whose scientific career spans over forty years. His books and public appearances have made him an academic celebrity and he is an Honorary Fellow of the Royal Society of Arts (Royal Society for the encouragement of Arts, Manufactures & Commerce), a lifetime member of the Pontifical Academy of Sciences, and in 2009 was awarded the Presidential Medal of Freedom, the highest civilian award in the United States.

Hawking was the Lucasian Professor of Mathematics at the University of Cambridge for thirty years, taking up the post in 1979 and retiring on 1 October 2009. He is also a Fellow (Oxbridge Fellow) of Gonville and Caius College, Cambridge and a Distinguished Research Chair at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario. He is known for his contributions to the fields of cosmology and quantum gravity, especially in the context of black holes. He has also achieved success with works of popular science in which he discusses his own theories and cosmology in general; these include the runaway best seller A Brief History of Time, which stayed on the British Sunday Times (The Sunday Times) bestsellers list for a record-breaking 237 weeks.

Hawkings key scientific works to date have included providing, with Roger Penrose, theorems regarding gravitational singularities (Gravitational singularity) in the framework of general relativity, and the theoretical prediction that black holes should emit radiation, which is today known as Hawking radiation (or sometimes as Bekenstein (Jacob Bekenstein)-Hawking radiation).

Hawking has a neuro-muscular dystrophy that is related to amyotrophic lateral sclerosis, a condition that has progressed over the years and has left him almost completely paralysed.