The Argyn (Kazakh: Арғын) tribe (or clan) is a constituent of the Kazakh ethnicity. The present-day Argyns of Kazakhstan are generally regarded as descended from a nomadic people known as the Basmyl and both names are said to mean "mixed tribe". The Argyn are a component, of the Orta jüz (Орта жүз; "Middle Horde" or "Middle Hundred"). Kazakhs historically consisted of three tribal federations: the Great jüz (or Senior jüz), Middle jüz, and Little jüz (or Junior jüz).
There is evidence for the Argyns' mixed origins in three facts. Firstly, while modern Argyns speak Kazakh, the Basmals were reported to have their own language. Secondly, the Argyns appear to be genetically linked to peoples of the Caucasus and dissimilar to most Kazakhs. Thirdly, the Basmals were first recorded in an area that is now in western China, and still home to a Kazakh minority.
The name of the Argyns probably corresponds to that of the "Argons" mentioned by Marco Polo in a country called "Tenduc" (around modern-day Hohot) during the 13th century. Polo reported that this clan who had "sprung from two different races: to wit, of the race of the Idolaters of Tenduc and ... the worshippers of Mahommet. They are handsomer men than the other natives of the country, and having more ability, they come to have authority; and they are also capital merchants."