What is the name of Stephen Hawking's PhD supervisor?

Stephen Hawking’s PhD supervisor was Dennis William Sciama. Sciama was a leading British physicist and is regarded as one of the founders of modern cosmology.

Hawking began his graduate work at Cambridge in 1962, studying general relativity and cosmology. He had initially hoped to work with the astronomer Fred Hoyle, but was assigned to Sciama instead. Sciama encouraged Hawking during a difficult period that included his diagnosis with motor neurone disease at age 21.

Under Sciama’s supervision, Hawking developed his research on singularities and the expanding universe. His PhD thesis, Properties of Expanding Universes, was approved in 1966. Hawking’s later scientific collaborations with Roger Penrose helped connect black-hole singularity theorems with the origin of the universe, but Penrose was not his doctoral supervisor. Kip Thorne and John Wheeler were also influential physicists, yet neither supervised Hawking’s PhD.