Voltaire was a French writer and philosopher. He was expelled from the French court by Louis XV in 1758. In the Shadow-Space version of France, the Fifth Doctor was said to be a friend of Voltaire. (AUDIO: Masquerade)
The Seventh Doctor quoted Voltaire when he told Sherlock Holmes that he was a doctor of "metaphysico-theologico-cosmologo-nigology". (PROSE: All-Consuming Fire)
On 26 March 2005, Yvonne Hartman told Mike that her brother was a bouncer who read Voltaire. (AUDIO: One Rule)