The Philopappu Monument (Greek: Μνημείο Φιλοπάππου) is an ancient Greek mausoleum and monument dedicated to Gaius Julius Antiochus Epiphanes Philopappos or Philopappus, (Greek: Γάιος Ιούλιος Αντίοχος Επιφανής Φιλόπαππος, 65–116 AD), a prince from the Kingdom of Commagene. It is located on Mouseion Hill in Athens, Greece, southwest of the Acropolis.
Philopappos died in 116, and his death caused great grief to his sister Julia Balbilla, citizens of Athens and possibly to the imperial family. As a dedication to honor the memory of Philopappos, Balbilla with the citizens of Athens erected a tomb structure on Muse Hill (Lofos Muson) near the Acropolis of Athens. His marble tomb monument is still known as the Philopappu Monument, and the hill is today known as Philopappu Hill (Λόφος Φιλοπάππου).
The Greek geographer Pausanias (Description of Greece, I.25.8), describes Philopappos’ grand tomb as a monument built for a Syrian man. The monument was built on the same site where Musaios or Musaeus, a 6th-century BC priestly poet and mystical seer, was held to have been buried. The location of this tomb, opposite the Acropolis and within formal boundaries of the city, shows the high position Philopappos had within Athenian society.
Philopappos’ monument is a two-storey structure, supported by a base. On the lower level there is a frieze representing Philopappos as a consul, riding on a chariot and led by lictors. The upper level shows statues of three men: of Antiochus IV on the left, of Philopappos in the centre and of Seleucus I Nicator, now lost, on the right.