Son of billionaire Aristotle Onassis and step-mother Jackie Onassis, whose foundation is responsible for many philanthropic efforts.
He attended the Institut Le Rosey in Switzerland.
After his untimely death in an airplane crash, The Alexander S. Onassis Foundation was founded in his name.
His father was Aristotle Onassis and his mother was Athina Livanos. He had a sister named Christina.
His father married Jacqueline Kennedy Onassis in 1968.