Yusuf Khass Hajib[a] was an 11th-century Central Asian Turkic poet, statesman, vizier, Maturidi theologian and philosopher from the city of Balasaghun, the capital of the Kara-Khanid Khanate in modern-day Kyrgyzstan.

Balasaguni started to work on the Kutadgu Bilig (Middle Turkic: Wisdom of Royal Glory) in Balasagun and was about 50 years old when he completed it in Kashgar.

[7] After presenting the completed work to the Karakhanid Hasan ibn Sulayman (father of Ali-Tegin) - Prince of Kashgar he was awarded the title Khāṣṣ Ḥājib, an honorific similar to "Privy Chamberlain" or "Chancellor".

The following is the excerpt from the Kutadgu Bilig; the first column is the text in the original (Karluk or Middle Turkic) language, but transliterated into Turkish (Latin) letters.

The mausoleum of the poet in Tainap, Kashgar was erected in 1865 by Yakub Beg of Yettishar but it was destroyed in 1972 during the Cultural Revolution and a school was built in its place.