His father, Gebran Tueni, founded Al-Nahar in 1933, seven years after Ghassan was born. A Greek Orthodox Christian, Tueni attended AUB, where he studied under Charles Malik, and was pursuing further studies at Harvard when he had to return to Beirut on his father's death in 1947. He took over Al-Nahar, and was its Editor-and Chief and Publisher from 1948 to 1999. and again in 2003.
His first wife, the poet Nadia Hamadeh, of a prominent Druze family, died of cancer; he lost a daughter, Nayla, quite young, and a son, Marwan, in an auto accident. His son and heir, both at Al-Nahar and in Parliament, also named Gebran Tueni after Ghassan's father, was assassinated in a car bombing in 2005 in the wake of the Hariri assassination. He is survived by his second wife, Shadia Al-Khazen, and several grandhildren.
Though his politics, like those of any Lebanese in the civil war era and since, made him both allies and enemies, his role as one of the most prominent Arab journalists of the 20th century is indisputable.