榆林市
Li Sijian () (died 908), probably né Tuoba Sijian (), was an ethnically-Dangxiang warlord in the latter years of Chinese Tang Dynasty and Tang's successor state Later Liang of the Five Dynasties and Ten Kingdoms Period, who controlled Dingnan Circuit (定難, headquartered in modern Yulin, Shaanxi) as its military governor ("Jiedushi") in "de facto" independence.