In Shakespeare's Hamlet, Prince Hamlet attends the University of Wittenberg. The play identifies Wittenberg when Claudius and Gertrude discuss Hamlet's return to Denmark and when Hamlet speaks about his student life and acquaintances there.
Wittenberg was a real university town in Saxony, founded in 1502 and later associated with Martin Luther and the Protestant Reformation. Shakespeare uses the location to suggest that Hamlet has received a humanist education in philosophy, rhetoric, theology, and classical learning. His intellectual outlook helps explain both his reflective temperament and his tendency to question appearances.
The university setting also contrasts with the corrupt royal court of Denmark. Hamlet returns from study after his father's death, but he is drawn into political intrigue, surveillance, and revenge. His famous soliloquies often sound like the work of a scholar testing ideas rather than a conventional revenge hero rushing toward action.
Readers sometimes choose Oxford or Cambridge because those universities are more familiar English institutions, but neither is named in the play. Padua is another Renaissance university city, yet it is not Hamlet's university. The name Wittenberg is therefore the fair, canonical answer.