Athina Mary Livanos Onassis Spencer-Churchill Niarchos (Greek: Αθηνά (Τίνα) Λιβανού; 19 March 1929 – 10 October 1974) was the second daughter of the Greek shipping magnate Stavros Livanos and Arietta Zafirakis. She was best known as the first wife of Aristotle Onassis, but she later married her older sister Eugenia's widower, Stavros Niarchos. She was older sister to her parents' only son, George Stavros Livanos.