Charon's obol is an allusive term for the coin placed in or on the mouth of a dead person before burial. Greek and Latin literary sources specify the coin as an obol, and explain it as a payment or bribe for Charon, the ferryman who conveyed souls across the river that divided the world of the living from the world of the dead. Archaeological examples of these coins, of various denominations in practice, have been called "the most famous grave goods from antiquity."The custom is primarily associated with the ancient Greeks and Romans, though it is also found in the ancient Near East. In Western Europe, a similar usage of coins in burials occurs in regions inhabited by Celts of the Gallo-Roman, Hispano-Roman and Romano-British cultures, and among the Germanic peoples of late antiquity and the early Christian era, with sporadic examples into the early 20th century.
Although archaeology shows that the myth reflects an actual custom, the placement of coins with the dead was neither pervasive nor confined to a single coin in the deceased's mouth. In many burials, inscribed metal-leaf tablets or Exonumia take the place of the coin, or gold-foil crosses during the early Christian period. The presence of coins or a coin-hoard in Germanic ship-burials suggests an analogous concept.The phrase "Charon’s obol" as used by archaeologists sometimes can be understood as referring to a particular religious rite, but often serves as a kind of shorthand for coinage as grave goods presumed to further the deceased's passage into the afterlife. In Latin, Charon's obol sometimes is called a viaticum, or "sustenance for the journey"; the placement of the coin on the mouth has been explained also as a seal to protect the deceased's soul or to prevent it from returning.