Yesugei Baghatur or Yesükhei (Modern Mongolian: Есүхэй баатар, Yesukhei baatar; died 1171), was a major chief of the Khamag Mongol confederation and the father of Temüjin, later known as Genghis Khan.
Yesügei was the son of Bartan Baghatur, who was the son of Khabul Khan, who was recognized as a khagan by the Jin Dynasty. Khabul Khan was, in turn, the grandson of the Mongol chief Khaidu, the first to try to unite all of the Mongols. Yesugei had two sons by his first wife: Behter and Belgutei. The Secret History of the Mongols records that in his youth Temüjin killed his brother Behter in a fight for food. His other half-brother, Belgutei, however was a good friend, and later became a general under Genghis. Yesügei's second and chief wife, Hoelun (a daughter of the Olkhunut forest tribe) was abducted by Yesügei and his brothers from her newlywed husband.
Yesügei's children by Hoelun consisted of the four sons Temüjin, (later known as Genghis Khan), Hasar, Hachiun, Temüge (son), and one daughter, Temülen.