The Bollywood superstar was presented the degree by Les Ebdon, vice chancellor of the university, for his contribution to Indian cinema and culture.
Khan, who wore the traditional scholar's robe and cap, was nominated by Routes to Roots, an NGO that works to bring South Asian people together.
At the degree ceremony, the 43-year-old actor joked: "Interestingly my kids don't understand this doctorate and believe I will be awarded a stethoscope."
Other Indian film industry figures to receive honorary doctorates in the UK include Amitabh Bachchan, Shilpa Shetty, Akshay Kumar and A.R. Rahman.