Pithos (plural pithoi) originally referred in ancient Greek (πίθος, πίθοι) to a large storage jar of a characteristic shape. The word was at one point used by western classical archaeologists to mean the jars uncovered by excavation in Crete and Greece. It has now been adopted by the American English language as a general word for a storage jar from any culture.

Although the word is Greek, many of the pithoi of the ancient Mediterranean were not produced on the Greek mainland; for example, they are known from Crete and the Levant in non-Hellenic contexts. Many pithoi were excavated in the Palace of Knossos and the ancient shipwreck of Uluburun. The Ancient Iberian culture of El Argar also used pithoi for burials in its B phase (1500-1300 BC).

The pithos is better known in its Latin form as the fiscus, sometimes taken as meaning a place where funds were stored. Anything could be placed in a pithos; however, they were used primarily for grains, seeds, wine, and oil. They were commonly associated with administrative and trade centers, which shipped, kept, or received large quantities.