Xian Gu 先縠 (died 596 BCE), courtesy name Zhizi 彘 or Yuan Gu 原縠, was a nobleman in the state of Jin 晉 during the Spring and Autumn period 春秋 (770-5th cent. BCE), and a member of the house of Xian 先. He was a son of Xian Zhen 先軫 and served Duke Jing 晉景公 (r. 600-581) as a military commander.
In 597, King Zhuang of Chu 楚莊王 (r. 613-591) besieged the state of Zheng 鄭. Asked for support, the duke of Jin sent out Xun Linfu 荀林父 to bring relief. Xian Gu participated in the campaign as assistant commander of the Central Army (zhongjun zuo 中軍佐). Before the army of Jin arrived in the war theatre, news came from the surrender of the duke of Zheng. While Xun Linfu wanted to return, Xian Gu insisted in fulfilling the ducal order to rescue the state of Zheng. The result was that the army of Chu crushed the troops of Xian Gu.
Fearing punishment for his overhasty engagement he considered asking for the support of the Red Di tribes 赤狄 to rebel against Duke Jing. Yet his plan was reveiled and he was executed.