Tian Ji 田忌 was a general of the state of Qi 齊 during the Warring States period 戰國 (5th cent-221 BCE). He is also called Tian Qi 田期 or Tian Qisi 田期思. His territory was Xuzhou 徐州, for which reason he is also found under the name Xuzhou Ziqi 徐州子期.
In 353, he helped Sun Bin 孫臏, general of Zhao 趙, to besiege the capital of the state of Wei 魏, Daliang 大梁. The army of Wei was defeated at Guiling 桂陵 (northwest of modern Changyuan 長垣, Henan).
In 341, he again took part in a joint campaign against Wei, together with Tian Ying 田嬰, Tian Pan 田盼 and Sun Bin. After the battle of Maling 馬陵 (southwest of modern Fanxian 范縣, Henan) the heir apparent of Wei, Prince Shen 申, and general Pang Juan 龐涓, were captured. When Tian Ji was slandered by Counsellor-in-chief Zou Ji 鄒忌, he had to flee to Chu 楚, where he was made governor (taishou 太守) of Jiangnan 江南, and eventually died there.