thumb|200px|[[Kroisos Kouros, ]]
Kouros (, , plural kouroi) is the modern term given to free-standing Ancient Greek sculptures that depict nude male youths. They first appear in the Archaic period in Greece and are prominent in Attica and Boeotia, with a less frequent presence in many other Ancient Greek territories such as Sicily.
Such statues are found across the Greek-speaking world; the preponderance of these were found in sanctuaries of Apollo with more than one hundred from the sanctuary of Apollo Ptoion, Boeotia, alone.
These free-standing sculptures were typically marble, but the form is also rendered in limestone, wood, bronze, ivory and terracotta. They are typically life-sized, though early colossal examples are up to 10 feet/3 metres tall.
The female sculptural counterpart of the kouros is the kore.
Etymology
The Ancient Greek word kouros () refers to "youth, boy, especially of noble rank."
When a pubescent was received into the body of grown men, as a grown Kouros, he could enter the initiation fest of the brotherhood (phratry, ). Apellaios was the month of these rites, and Apollo (Apellon) was the "megistos kouros" (the greatest Kouros).
The word is also attested in Linear B, a syllabary system of writing used to record the Mycenaean Greek dialect of the Hellenic languages. The word ko-wo (, *kórwos) is attested in tablets from Pylos and Knossos, and could mean "the sons of the women recorded in those tablets". This association with Apollo was supported by the description of the statue of the Pythian Apollo at Samos by Diodoros and some kouroi have been found in sanctuaries other than that of Apollo. Indeed, some kouroi placed in sanctuaries were not inscribed with the name of the god but with a mortal, for example the 'Delphi Twins' Kleobis and Biton were honoured for their piety with matching kouroi.
Origin and evolution
The evolution of the kouros type is inevitably linked to that of the overall development of monumental Archaic Greek sculpture. There are fundamentally two schools of thought on how Daedalic forms, some of which we know of only from the literature (kolossos, bretas, andrias and xoanon), became the free-standing sculpture in around the 6th century; namely, that it was a response to the internal development of Greek types and religious needs or a product of foreign influence. For an external cause for change, possible sources of influence have been cited, such as Egypt, Anatolia and Syria, with the strongest case made for Egypt, in particular the figure of Horus. It is known that the Greeks had longstanding trade relations with Egypt prior to the founding of the Greek entrepôt of Naukratis in the mid-7th century,
where the Greeks could have learned Egyptian sculpting methods.