King Wei of Qi

King Wei of Qi (Chinese: 齊威王; pinyin: Qí Wēi Wáng), whose personal name was Tian Yinqi (田因齊), was the king of the northern Chinese state of Qi during the Warring States period, when Qi was one of the most powerful states in China. He reigned from 356 to 320 BC. or according to another source from 378 to 343 BC.

His successor was King Xuan of Qi. In the Intrigues of the Warring States, the strategist Su Qin is quoted as telling the king of Qin: "Kings Wei and Xuan of Qi were the worthiest rulers of their age. Their power was great and their lands were broad. Their states were wealthy and their citizens capable. Their generals were aggressive and their troops strong."

King Wei was judicious and measured in his actions toward his subordinates. At one point he was told repeatedly by his spies that one of his generals, Zhangzi, had surrendered to the enemy, Qin. King Wei refused to believe that Zhangzi had deserted. Sure enough, "a short while later it was reported that Qi had won a great victory. The king of Qin proclaimed himself a vassal of the western borders and made his apologies to Qi." King Wei said that he always knew Zhangzi was faithful and cited this story in his defence.