- For the Roman-era writer, see Pomponius Porphyrion.
- "Porphyrion" is also a section of the genus Saxifraga.
In Greek mythology, Porphyrion (Greek: Πορφυρίων) was one of the Gigantes (Giants), who according to Hesiod, were the offspring of Gaia, born from the blood that fell when Uranus (Sky) was castrated by their son Cronus. In some other versions of the myth, the Gigantes were born of Gaia and Tartarus, the god of the pit.  According to the mythographer Apollodorus, Porphyrion was (along with Alcyoneus), the greatest of the Giants, and during the Gigantomachy, the battle between the Giants and the Olympian gods, Porphyrion attacked Heracles and Hera, but Zeus caused Porphyrion to become enamoured of Hera, whom Porphyrion then tried to rape, but Zeus struck Porphyrion with his thunderbolt and Heracles killed him with an arrow. According to Pindar, who calls him "king of the Giants", he was slain by an arrow from the bow of Apollo.
The late fourth century AD Latin poet Claudian in his Gigantomachia has Gaia, imagining the Giants victorious, propose that "Porphyrion, wreathe thou thy head with Delphi's laurel and take Cirrah for thy sanctuary", and has Porphyrion attempt "to uproot trembling Delos, wishing to hurl it at the sky". The late fourth or early fifth century AD Greek poet Nonnus, in his Dionysiaca, has Gaia set the Giants against Dionysus, promising Porphyrion Hebe as his wife should the Giants subdue Dionysus.
Porphyrion is named on a sixth century BC black-figure pyxix (Getty 82.AE.26), where he and the Giant Enceladus oppose Zeus, Heracles and Athena. He is also named on a late fifth century BC red-figure cup from Vulci (Berlin F2531), and a fifth century BC red-figure krater (Paris, Petit Palais 868), in both engaged in single combat with Zeus, and a late sixth century early fifth century fragmentary BC red-figure cup (British Museum E 47), where his opponent is lost.
Porphyrion was probably named on the Gigantomachy depicted on the north frieze of the Siphnian Treasury at Delphi (c. 525 BC), and he was one of the many Giants depicted on the second century BC Pergamon Altar Gigantomachy frieze, where he is shown fighting Zeus.
- For the birth of the Gigantes see Hesiod, Theogony 185. Hyginus, Fabulae Preface gives Tartarus as the father of the Giants.
- Apollodorus, 1.6.1–2. Compare with Aristophanes, The Birds 1249 ff.: "a single Porphyrion gave him [Zeus] enough to do."
- Pindar, Pythian 8.12–18.
- Claudian, Gigantomachia 34–35 (pp. 282–283).
- Claudian, Gigantomachia 114–116 (pp. 288–289).
- Nonnus, Dionysiaca, 48.6–22 (pp. 424–427).
- Beazley Archive 10148 Fragment: Heracles, Athena, horses of Zeus' chariot, Porphyrion and Enceladus.
- Berlin F2531: Beazley Archive 220533: detail showing Zeus v. Porphyrion; Cook, p. 56, Plate VI. Paris, Petit Palais 868: Arafat, p. 184; Beazley Archive 206859.
- Arafat, pp. 16, 184; Sparks, p. 27; Beazley Archive 203256; LIMC Gigantes 301.
- Brinkmann, N22 p.103, which finds traces of "rion"; Stewart, plate 196.
- Ridgeway, p. 54 note 35.
- Apollodorus, Apollodorus, The Library, with an English Translation by Sir James George Frazer, F.B.A., F.R.S. in 2 Volumes. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1921. Online version at the Perseus Digital Library.
- Claudian, Claudian with an English translation by Maurice Platnauer, Volume II, Loeb Classical Library No. 136. Cambridge, MA: Harvard University Press; London: William Heinemann, Ltd.. 1922. ISBN 978-0674991514. Internet Archive.
- Arafat, K. W., Classical Zeus: A Study in Art and Literature, Clarendon Press, Oxford 1990. ISBN 0-19-814912-3.
- Cook, Arthur Bernard, Zeus: A Study in Ancient Religion, Volume III: Zeus God of the Dark Sky (Earthquakes, Clouds, Wind, Dew, Rain, Meteorites), Part I: Text and Notes, Cambridge University Press 1940. Internet Archive
- Hesiod, Theogony, in The Homeric Hymns and Homerica with an English Translation by Hugh G. Evelyn-White, Cambridge, MA.,Harvard University Press; London, William Heinemann Ltd. 1914. Online version at the Perseus Digital Library.
- Hyginus, Gaius Julius, The Myths of Hyginus. Edited and translated by Mary A. Grant, Lawrence: University of Kansas Press, 1960.
- Nonnus, Dionysiaca; translated by Rouse, W H D, III Books XXXVI–XLVIII. Loeb Classical Library No. 346, Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1940. Internet Archive
- Pindar, Odes, Diane Arnson Svarlien. 1990. Online version at the Perseus Digital Library.
- Ridgway, Brunilde Sismondo, Hellenistic Sculpture II: The Styles of ca. 200-100 B.C., University of Wisconsin Press, 2000. ISBN 978-0299167103.
- Sparks, Brian A., "Aspects of Onesimos" in Greek Art: Archaic Into Classical : a Symposium Held at the University of Cincinnati April 2-3, 1982, BRILL, 1985. ISBN 9789004070790.* Stewart, Andrew F., Greek Sculpture: An Exploration, Yale University Press, 1990.