Antonia the Elder[a] (born August/September 39 BC) was a niece of the first Roman emperor, Augustus, being the eldest daughter of Octavia the Younger and her second husband, the Triumvir Mark Antony.

[2][3] Syme thinks its possible that the daughter may have lived to marry and produce children, but probably died before the reign of Caligula.

[4] Many scholars think the Ara Pacis (an altar from the Augustan Era), displays Gnaeus Domitius Ahenobarbus and his elder sister.

Sir Ronald Syme has argued the two children are actually a lost elder son Lucius and another unknown sister.

No surviving source mentions older siblings who died in childhood, whereas there are other branches of the imperial family that had exactly one son and one daughter between 21 and 15 BC.