Alexander Helios (40 BC - ? ) was the son of Cleopatra VII of Egypt and Marcus Antonius and the twin brother of Cleopatra Selene.

Although they were still children, for reasons of state he was married to Iotapa (b. 43 BC), daughter of the king of Media, in 33 B.C.. In the Autumn of 34 BC, at the "Donation of Alexandria", Alexander was crowned ruler of Armenia, Media and Parthia. Those titles were largely nominal, however, because all three thrones were already occupied by others, respectively Artavasdes II of Armenia, Artavasdes I of Media and Phraates IV of Parthia. His parents probably intended that he should succeed to those thrones in due course.

After Caesar Augustus invaded Egypt and his parents committed suicide, his sister, Cleopatra Selene and younger brother, Ptolemy Philadelphus, were taken to Rome and paraded through the streets in golden chains. The three siblings were raised by Marcus Antonius's ex-wife and sister of Caesar Augustus, Octavia. But after Cleopatra Selene married Juba II, him and his younger brother disappear. It is suspected that they were murdered, coincidentally the same time Herod was visiting in Rome, and with Herod's hate for the Ptolemaic Dynasty, it is highly supected that he may have convinced Octavian to get rid of the two boys.