Gu Yanlang (顧彥朗) (d. 891) was a warlord late in the Chinese Tang dynasty who controlled Dongchuan Circuit (東川, headquartered in modern Mianyang, Sichuan) from 887 to his death in 891 as its military governor (jiedushi).
Both he and his younger brother Gu Yanhui served as junior officers at Tiande (天德, in modern Bayan Nur).
[1] Meanwhile, a former colleague of Gu Yanlang's in the imperial guards corps, Wang Jian, had seized Lang Prefecture (閬州, in modern Nanchong, Sichuan) and claimed the title of prefect, and was sending the troops under him to raid the nearby regions.
Emperor Zhaozong thereafter commissioned the chancellor Wei Zhaodu as the new military governor of Xichuan and summoned Chen back to Chang'an to serve as a general of the imperial guards.
When Chen refused, Emperor Zhaozong declared a general campaign against Chen, with Wei in command and Gu, Wang, and Yang Shouliang the military governor of Shannan West Circuit (山南西道, headquartered in modern Hanzhong, Shaanxi) serving as Wei's deputies.
By 891, Chen was in a desperate state, but the imperial government's resources had become drained due to a recent defeat in a campaign against another warlord, Li Keyong the military governor of Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi).