Rhoemetalces Philocaesar (Greek: Ροιμητάλκης Φιλοκαῖσαρ; his epithet Philocaesar means in Greek "lover of Caesar") was a prince from Anatolia who lived in the Roman Empire in the 1st century.
Rhoemetalces was a prince of Greek, Roman, Assyrian, Armenian and Median ancestry. He was the second son born to the Roman client monarchs Polemon II of Pontus and Julia Mamaea, while his brother was Polemon. His father was the second son among the three children born to the Roman client monarchs Polemon I of Pontus, also known as Polemon Pythodoros and Pythodorida of Pontus. His mother was the second daughter born among four children to the Roman client monarchs Sampsiceramus II and Iotapa of Emesa, Syria.
The full name of Rhoemetalces is unknown. Rhoemetalces is known from a restored surviving inscription from Amphipolis, Greece, that commemorates Polemon II, Polemon and Rhoemetalces, and which is dated from the second half of the 1st century.
Perhaps his full name was Marcus Antonius Rhoemetalces Philocaesar. Rhoemetalces was named in honor of his late paternal first cousin Rhoemetalces II, a Roman client king of the Odrysian kingdom in Thrace who was contemporary with the reign of the emperor Tiberius (14–37). He is the first non-Thracian prince to bear the name Rhoemetalces, while the second was the Roman client King of the Bosporus, Tiberius Julius Rhoemetalces of the 2nd century. The epithet Philocaesar, recalls his maternal uncle, Roman client king Sohaemus of Emesa, who also used this epithet. The epithet Philocaesar is also shared by his various maternal relations, the Roman client kings of the Bosporan Kingdom.
Rhoemetalces was born at an unknown date perhaps between the early 50s and the early 60s. He was raised in his parents’ realms of Pontus, Colchis and Cilicia, and little is known of his life. In 62, the Roman emperor Nero induced Polemon II to abdicate the Pontian throne, and Pontus, with Colchis, became a Roman province. From then until his death, Polemon II only ruled Cilicia. When Polemon II died in 74, neither Rhoemetalces nor Polemon succeeded their father to the throne of Cilicia, as Cilicia became a Roman province.