Xi Gu 郤縠 (died 632) was a nobleman from the house of Xi 郤 in the state of Jin 晉 during the Spring and Autumn period 春秋 (770-5th cent. BCE).
He served Duke Wen 晉文公 (r. 637-628) as general of the Central Army (zhongjun 中軍), his relative Xi Zhen 郤溱 (also written 郤臻) being assistant commander. He had been recommended by Zhao Shuai 趙衰 (Zhao Chengzi 趙成子) because of his expertise in the rituals, ceremonial music and the classic writings of antiquity, based upon which he exerted command and leadership.
The Three Armies (sanjun 三軍) were a new creation by Duke Wen established in 633.The position of marshal of the Central Army corresponded to chief minister. He died during a campaign against the states of Cao 曹 and Wei 衛.