The Kutadgu Bilig or Qutadğu Bilig is an 11th-century work written by Yūsuf Balasaguni for the prince of Kashgar. The text reflects the author's and his society's beliefs, feelings and practices with regard to quite a few topics and depicts interesting facets of various aspects of life in the Kara-Khanid Khanate.

Yusuf Khass Hajib 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. He wrote the Kutadgu Bilig and most of what is known about him, comes from his own writings in this work. He is mostly referred to as Yūsuf Balasaguni, derived from his city of origin.