Aristotle Socrates Onassis (Greek: Αριστοτέλης Ωνάσης, Aristotelis Onasis; 20 January 1906 – 15 March 1975),[1] commonly called Ari or Aristo Onassis, was a Greek-Argentine shipping magnate, who amassed the world's largest privately owned shipping fleet and was one of the world's richest and most famous men.