古突厥文

The Old Turkic script (also known as variously Göktürk script, Orkhon script, Orkhon-Yenisey script) is the alphabet used by the Göktürk and other early Turkic Khanates during the 8th to 10th centuries to record the Old Turkic language.

The script is named after the Orkhon Valley in Mongolia where early 8th-century inscriptions were discovered in an 1889 expedition by Nikolay Yadrintsev. These Orkhon inscriptions were published by Vasily Radlov and deciphered by the Danish philologist Vilhelm Thomsen in 1893.

This writing-system was later used within the Uyghur Empire. Additionally, a Yenisei variant is known from 9th-century Kyrgyz inscriptions, and it has likely cousins in the Talas Valley of Turkestan and the Old Hungarian script of the 10th century. Words were usually written from right to left.

Thomsen characterized the script as 「Turkish runes」, and it is still occasionally described as Runic or 「runiform」 by comparison to the Old Germanic alphabet that were used during roughly the same period.