Ptolemy XV Caesar[lower-alpha 1] (/ˈtɒləmi/; Koinē Greek: Πτολεμαῖος, Ptolemaĩos; 23 June 47 BC – August 30 BC), nicknamed Caesarion (Καισαρίων), was the last pharaoh of ancient Egypt, reigning with his mother Cleopatra from 2 September 44 BC until her death by 12 August 30 BC, and as sole ruler until his death was ordered by Octavian, who would later become the first Roman emperor as Augustus.

Caesarion, from the "Unravel the Mystery" Cleopatra exhibit
Pharaoh of Ptolemaic Egypt
SuccessorAugustus (Roman emperor)
Born23 June 47 BC
Ptolemaic Kingdom
Diedlate August 30 BC (aged 17)
Alexandria, Roman Egypt
Koine GreekΠτολεμαῖος Φιλοπάτωρ Φιλομήτωρ Καῖσαρ, Καισαρίων
TransliterationPtolemaĩos Philopátōr Philomḗtōr Kaĩsar, Kaisaríōn
HouseJulio-Claudian (patrilineal)
Ptolemaic (matrilineal)
FatherJulius Caesar

Caesarion was the eldest son of Cleopatra and the only known biological son of Julius Caesar, after whom he was named. He was the last sovereign member of the Ptolemaic dynasty of Egypt.