The obol (Greek: ὀβολός, obolos, also ὀβελός (obelós), ὀβελλός (obellós), ὀδελός (odelós). lit. "nail, metal spit";^[1]bolo/s) Latin: obolus) was a form of ancient Greek currency and weight.

Obols were used from early times.

According to Plutarch they were originally spits of copper or bronze traded by weight, while six obols make a drachma or a handful, since that was as many as the hand could grasp.^[2]*.html#ref39]]eraklides of Pontus]]in his work on Ephorus on his work n Inventionsat Argos discovered several dozen of these early obols, dated well before 800 BC; they are now displayed at the Numismatic Museum of Athens. Archaeologists today describe the iron spits as "utensil-money" since excavated hoards indicate that during the Late Geometric period they were exchanged in handfuls (drachmae) of six spits,^[3] they were not used for manufacturing artifacts as metallurgical analyses suggest, but they were most likely used as token-money.^[4] Plutarch states the Spartans had an iron obol of four coppers. They retained the cumbersome and impractical bars rather than proper coins to discourage the pursuit of wealth.^[5]

In Classical Athens, obols were traded as silver coins. Six obols made up the drachma. There were also coins worth two obols ("diobol") and three obols ("triobol"). Each obol was divisible into eight "coppers" (χαλκοί, khalkoí). During this era, an obol purchased a kantharos and chous (6 pints or 3 liters) of wine.^[6] Three obols was a standard rate for prostitutes.

The deceased were buried with an obol placed in the mouth of the corpse, so that—once a deceased's shade reached Hades—they would be able to pay Charon for passage across the river Acheron or Styx. Legend had it that those without enough wealth or whose friends refused to follow proper burial rites were forced to wander the banks of the river for one hundred years.

The obol ^[7].%22]]r obolus ^[8] o a measurement of Greek, Roman, and apothecaries' weight.

In ancient Greece, it was generally reckoned as 1⁄6 drachma (c. 0.72 grams (0.025 oz)).^[9][10] Under Roman rule, it was defined as 1⁄48 of a Roman ounce or about 0.57 grams (0.020 oz).^[11] The apothecaries' system also reckoned the obol or obolus as 1⁄48 ounce or 1⁄2 scruple.

The obolus, along with the mirror, was a symbol of new schismatic heretics in the short story "The Theologians" by Argentine author Jorge Luis Borges.^[12] In the story's discussion of the circularity of time, eternity, and the transmigration of the soul through several bodies the author uses a quotation of Luke 12:59, mistranslated as "no one will be released from prison until he has paid the last obolus"^[12] since Luke calls the coin a lepton (a somewhat smaller denomination) rather than an obolus.