Athina Maria "Tina" Onassis Niarchos (, ; 19 March 1929 – 10 October 1974) was an English-born Greek-French socialite and shipping heiress, the second daughter of the Greek shipping magnate Stavros Livanos and Arietta Zafirakis. She was known best as the first wife of Aristotle Onassis, but she later married her older sister Eugenia's widower, Stavros Niarchos. She was also the elder sister of George Stavros Livanos.

Marriages and family

She was married three times. Her husbands were: After her divorce from Aristotle Onassis, she resumed using her maiden name, Livanos, until her marriage to Spencer-Churchill. Her son with Onassis, Alexander Onassis, died at the age of 24 on 23 January 1973, as a result of injuries sustained during an airplane crash in Athens. Athina Niarchos died on 10 October 1974 in the Hôtel de Chanaleilles, the Parisian mansion that she shared with her husband. Her death was officially ruled by pathologists as having resulted from an acute edema of the lung, but has also been attributed to her suffering a drug overdose. She was buried next to her sister at the Bois-de-Vaux Cemetery in Lausanne, Switzerland. Her daughter, Christina Onassis, sued Stavros Niarchos, her mother's widower, for her mother's estimated US$250 million (in 1974 dollars) estate, claiming the marriage should be annulled by Greek law. Christina later ended the lawsuit and Niarchos returned all of his wife's money as well as her jewelry, artwork and other personal effects to Christina. Her only living descendant is her namesake granddaughter, Athina Onassis, Christina's daughter.