As Jayne Nelson wrote, Stephen Hawking was a Physics undergraduate at University College, Oxford before taking his postgraduate studies at Cambridge.
No mention was made however of Stephen's Physics Tutor at Univ, the late Dr Bobby Berman who has inspired Oxford University's Berman Graduate Scholarships.  Bobby was Univ's Fellow in Physics for 28 years from 1955 and I had the benefit of his supervisory skills for my D.Phil research in experimental low temperature physics at the Clarendon Laboratory during 1968-72. 
On Saturday 28th April 1984, I presented a postgraduate perspective of Bobby entitled "The Renaissance Man" on the occasion of his Valedictory Dinner in the Arlington Room at Univ. At some stage Bobby mentioned to me, in characteristic modesty, that he had tutored Stephen in his first year at Univ, thereafter Stephen taught him!
Dr Paul Hudson
University, 1968