Is Oxford University older than the Aztec Empire?

Yes. Teaching at Oxford is documented from 1096 and grew quickly after 1167. The Aztec Empire, the Triple Alliance of Tenochtitlan, Texcoco and Tlacopan, was formed in 1428. Oxford had been teaching for over 300 years when the Aztec Empire began, and the Empire lasted less than a century before the Spanish conquest of 1521.

Source: University of Oxford, 'Introduction and history'; Smith, The Aztecs (3rd ed., 2012)