Jisun Su 季孫宿 (died 535 BCE), posthumous title Ji Wuzi 季武子, was a chief minister in the feudal state of Lu 魯 during the Spring and Autumn period 春秋 (770-5th cent. BCE). He was the son of Jisun Xingfu 季孫行父 from the house of Jisun 季孫 and reigned between 561 and 535 under Duke Xiang 魯襄公 (r. 573-542).
At that time the ducal house of Lu had lost ist power to the Three Huan families 三桓, descendants of Duke Huan 魯桓公 (r. 712-694) and lateral branches to the ruling house. In 562 Jisun Su created the three armies (sanjun 三軍), yet Shusun Bao 叔孫豹 (Shusun Muzi 叔孫穆子) argued that the family Jisun alone would barely be able to bear the burden of reigning Lu. The three families therefore decided to divide power and competence among them. In 537 the three armies were merged into two.
In 561, the statelet of Ju 莒 besieged the town of Tai 邰 (near modern Feixian 費縣, Shandong), in 588 the state of Qi 齊 in the north attacked the town of Cheng 成 (near modern Ningyang 寧陽, Shandong). Jisun Su and Shusun Bao liberated the two towns. In 541 Duke Zhao himself occupied the town of Yun 鄆 that belonged to Ju. Jisun Su's last political mission was a visit to the state of Jin that had supported Lu in a very successful campaign against Qi.