The Basmyls are a seventh–eighth century Türkic nomadic tribe who mostly inhabit the Dzungaria region in the northwest of the modern day People's Republic of China.

According to literary sources, the terms Basmyls and Basmals are readily interchangeable.

Basmyls play a prominent role in the Eastern Türkic Kaganate, and at one time are the dynastic tribe who lead the Khaganate.

They later merge with the Karluk and Yagma tribes and create the Kara-Khanid state.Basmyls are the first to use the term Idyk-kut, which replaces khagan in the titles of the Uyghur rulers of Turpan.

The second component kut/qut in the title is often found in Old Turk onomastics and titulature and has the lexical meaning "grace of heaven" or "blessing".

The Tszychji tuntszyan records that in 720 the dynastic Basmal clan were Ashina who were descended from the Turkic peoples (Ch.

pinyin Tu-jue).

Today's Argyns in the Kazakh Middle Juz are the former Basmals – these names are linguistically equivalent and mean "mixed tribe".

In the thirteenth century, Marco Polo records that the prevailing tribe of Tanduk are Argon Christians (i.e.

Argyns), which means Basmul.

The mixed origins of the Basmals are confirmed by their comprising forty clans, as opposed to the three tribes of Karluks, nine tribes of Uyghurs and ten tribes of the Jeti-su Türks.

Early Middle Age locations for the Basmals are given in the Tszychji tuntszyan, where the Basmals' residence is named as Beitin, on the Bogdoshan ridge in the Guchen area.

Turkic scholar Mahmut Kashgari of the eleventh century lists the Basmyls as one of ten prominent Türkic tribes and enumerates the locations of the Türkic polities from the borders of Greece to the borders of China in the following sequence: Bechen (Badjinak), Kyfchak (Kipchak), Oguz, Yemek (Kimek), Bashgyrt (Bashkort), Basmyl, Kai, Yabaku, Tatars, Kyrgyz.

Kashgari also noted that the Kai, Yabaku, Tatar, and Basmyl tribes are all bilingial, speaking Türkic alongside their own languages, while peoples including the Kyrgyzes, Kyfchaks, and Oguzes have their own Türkic languages, which are related to the languages of the Yemeks and Bashkirts.