Archimedes

Archimedes (287-212 BC) was a Greek mathematician and scientist, generally regarded as one of the greatest thinkers in history.

The First Doctor claimed to have met Archimedes. (PROSE: City at World's End) The Eighth Doctor also claimed to have met Archimedes. (PROSE: Fallen Gods)

Other references
During his show, Herbert Clegg made a joke about him and his notorious claim "Eureka!". (TV: Planet of the Spiders)