Kul Tigin (Old Turkic: 𐰚𐰇𐰠𐱅𐰃𐰏𐰤, romanized: Kültegin Chinese: 闕特勤, Pinyin: Quètèqín, Wade–Giles: chüeh-t'e-ch'in, 684–731) was a general and a prince of the Second Turkic Khaganate.

Necip Asım (1921) initially gave his name as köl, based on the etymology of Mahmud al-Kashgari, meaning "lake, sea". Radloff rendered this word as kül, and Thomsen (1896), Malov (1951) and Tekin (1968) adopted this reading. Bazin (1956) and Hamilton (1962) rejected Radloff's reading and preferred the form köl. However, Chinese sources used the Chinese character 闕 (què). Therefore, this word should be read as kül, not köl.

Kul Tigin was the second son of Ilterish Qaghan, the Second Turkic Khaganate's founder, and the younger brother of Bilge Qaghan (born Ashina Mojilian), the fourth qaghan. He was seven when his father died.

During the reign of Qapaghan Qaghan, Kul Tigin and his older brother earned reputation for their military prowess. They defeated the Yenisei Kyrgyz, Türgesh, and Karluks, extending the kaganate territory to the Iron Gate south of Samarkand. They also subjugated all nine of the Toquz Oghuz tribes.

In 705, Turkic forces commanded by Ashina Mojilian entered Lingwu, defeating Shazha Chongyi (沙吒忠义). Kul Tigin commanded a unit in battle, in which he lost three horses.

In 711, he participated in Battle of Bolchu, which was disastrous for the Türgesh.

In 712, the Arab general Qutayba ibn Muslim besieged Samarkand after capturing Khwarazm. The prince of Samarkand appealed to the king of Tashkent for aid. Qapaghan Qaghan, who had become overlord of both Tashkent and Ferghana, dispatched Kul Tegin at the head of a combined army of Eastern turks, Tashkent forces, and Ferghana troops to relieve the besieged city. Despite the strength of the Turkish forces, Qutayba ultimately defeated Kul Tegin's army, forcing the Turks to withdraw and allowing the Umayyads to enter Samarkand and establish a garrison there.

In 713 he participated in subjugation of Karluk tribes with his brother and uncle.