Stephen William Hawking (born 8 January 1942) is a British theoretical physicist. Hawking is the Lucasian Professor of Mathematics at the University of Cambridge, and a Fellow of Gonville and Caius College, Cambridge. He is known for his contributions to the fields of cosmology and quantum gravity, especially in the context of black holes, and his popular works in which he discusses his own theories and cosmology in general. These include the runaway popular science bestseller A Brief History of Time, which stayed on the British Sunday Times bestseller list for a record-breaking 237 weeks.

His key scientific works to date have included providing, with Roger Penrose, theorems regarding singularities 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-Hawking radiation. His scientific career spans more than 40 years and his books and public appearances have made him an academic celebrity and world-renowned theoretical physicist. He is an Honorary Fellow of the Royal Society of Arts. Hawking is disabled by amyotrophic lateral sclerosis (ALS). The illness has progressed over the years and he is now almost completely paralysed.