Lü Kai (birth and death dates unknown), courtesy name Jiping, was an official of the state of Shu Han during the Three Kingdoms period. He served as the Administrator of Yongchang commandery (永昌郡). He defended it from Yong Kai's rebel forces at one time. During Zhuge Liang's Southern Campaign, he presented Zhuge Liang with a map of the Nanzhong region and served as a guide for the army.