Heracleium or Herakleion () was a city on the south coast of ancient Pieria, Macedon, between Phila and Leibethra. During Peloponnesian war it passed into Athenian control in the years 430/29, 425/4 and 421 BCE. After Athenian alliance with Perdiccas II in 413 BCE it became again a city of Macedon.
The site of Heracleium is near the modern Platamon.
References
The Athenian Tribute Lists by Benjamin D. Meritt
An Inventory of Archaic and Classical Poleis By Mogens Herman Hansen, Thomas Heine Nielsen Two Studies in Ancient Macedonian Topography - Page 46 by Miltiadēs V. Chatzopoulos, Louiza D. Loukopoulou CNN Transcript: Archaeologists Discover Ancient Cities Under Mediterranean