The Siphnian Treasury was a building at the Ancient Greek cult centre of Delphi, erected to host the offerings of the polis, or city-state, of Siphnos.

It was one of a number of treasuries lining the "Sacred Way", the processional route through the Sanctuary of Apollo, erected to win the favor of the gods and increase the prestige of the donor polis.

[1] Until recently it was often confused or conflated with the neighbouring Cnidian Treasury, a similar but less elaborate building, as the remains of the two had become mixed together and earlier theoretical reconstructions used parts of both.

[2] The people of Siphnos had gained enormous wealth from their silver and gold mines in the Archaic period (Herodotus III.57) and used the tithe of their income to erect the treasury, the first religious structure made entirely out of marble.

In his account, Herodotus states that the Siphnians had recently founded a temple at Delphi when a group of Samians arrived asking for support against the tyrannical Polycrates.

In respect to this, both Herodotus and Thucydides state that Polykrates ruled during the reign of the Persian king Kambyses (c. 529–522 BC).

The pronaos is distyle in antis, i.e., the side walls (Latin antae) extend to the front of the porch, and the pediment is supported by two caryatids instead of plain columns.

The reliefs were painted over with vivid shades of green, blue, red and gold, thus creating a unique sense of polychromy.

This type of opulent decoration featuring female figures full of motion and plasticity foreshadows the Caryatids erected subsequently at the Erechtheion on the Acropolis of Athens.

Heavily armed with helmets, shields, breastplates and greaves, they are attacking the gods from the right with spears, swords and stones.

The theme portrayed here is traditionally thought to be the Judgment of Paris, where the most beautiful goddess would be selected from among Aphrodite, Hera, and Athena.

Neer writes that the Judgement narrative has been somewhat forced upon this frieze, spending too much time on glaring blanks and not enough analyzing what little evidence is present.

Though little can confirm this figure's identity, there is a significant hint: palm trees are visible behind Artemis' horses, which is a common Attic painting device to indicate a desolate place.

Though this identification cannot be proven outright, it at least accounts for the palm trees, the unusual necklace, and the way that the goddesses appear to be leaving, an extremely uncommon posture in depictions of the Judgement of Paris.

However, the surviving fragments are the relief, well-sculpted horses portrayed full of energy, which prove the mastery of the artist.

In contrast, the artist of south and west side of the frieze insisted on more conservative options, without the bold inspiration and craftsmanship of the first, but with a strong painter-like character and an ionic 'color'.