Posidonius (disambiguation)

Posidonius or Poseidonios may refer to:


 * Poseidonios the Macedonian (3rd century BC?), a siege engineer mentioned by Biton of Pergamon
 * Posidonius (1st century BC), Stoic polymath


 * Posidonius (bishop of Urgell), bishop between AD 814 and 823
 * Posidonius (crater), a lunar impact crater