Li Shigu (Chinese: 李師古; 778 – July 19, 806) was a general of the Chinese Tang dynasty, who, as the military governor (Jiedushi) of Pinglu Circuit (平盧, headquartered in modern Tai'an, Shandong), ruled the circuit in a de facto independent manner from the imperial regime.
Li Shigu was born in 778, during the reign of Emperor Daizong. His father Li Na was the military governor (Jiedushi) of Pinglu Circuit who ruled the circuit de facto independently from the imperial regime. He had one younger half-brother, Li Shidao. During Li Na's term as military governor, Li Shigu served as the prefect of Qing Prefecture (青州, in modern Weifang, Shandong), a position that Li Na himself had served while Li Shigu's grandfather Li Zhengji was military governor.
In 792, Li Na died, and the soldiers supported Li Shigu to succeed him. Later in the year, Emperor Daizong's son Emperor Dezong, then emperor, approved and made Li Shigu the new military governor. Meanwhile, Wang Wujun, the military governor of neighboring Chengde Circuit (成德, headquartered in modern Shijiazhuang, Hebei), taking Li Shigu lightly due to his youth, sent forces to De (德州, in modern Dezhou, Shandong) and Di (棣州, in modern Binzhou, Shandong) Prefectures — preparing to attack two forts that Li Na had built, Geduo and Sancha (三汊). Li Shigu sent the officer Zhao Gao (趙鎬) to defend against Wang's attack. Emperor Dezong then sent eunuchs to intervene; Wang then withdrew. Subsequently, by order of Emperor Dezong, Li Shigu tore down Sancha's walls, but thereafter often encouraged people who had offended the imperial government to join him. Meanwhile, whenever he sent staff members out for tasks, he would detain their wives and children; if any would turn against him and submit to the imperial government, he would slaughter their families, and therefore his subjects did not dare to do so. In 800, Emperor Dezong gave him the honorary chancellor designation of Tong Zhongshu Menxia Pingzhangshi (同中書門下平章事).