Li Huaiguang (Chinese: 李懷光; 729 – September 19, 785) was a leading general of the Chinese dynasty Tang Dynasty, of Mohe extraction. He was credited with saving Emperor Dezong in the face of an attack by the rebel Zhu Ci in 783 but, dissatisfied with the lack of trust that Emperor Dezong displayed in him later, also rebelled, but his rebellion was stunted by the refusals of many of his subordinates to follow him. In 785, facing defeat by Tang imperial forces, he committed suicide.
Li Huaiguang was born in 729, during the reign of Emperor Xuanzong. His ancestors were Mohe from Balhae, and had originally been surnamed Ru (茹). Li Huaiguang's father was originally named Ru Chang (茹常), but due to his accomplishments while serving as a soldier at Shuofang Circuit (朔方, headquartered in modern Yinchuan, Ningxia), was given the imperial surname of Li and a new personal name of Jiaqing (嘉慶).
Li Huaiguang started his military service when he was young, and he was known for his abilities in martial arts, his bravery, and his strength. He served under Guo Ziyi, who was then serving as the military governor (Jiedushi) of Shuofang Circuit and who respected him greatly. Early in the Shangyuan era (760–762) of Emperor Xuanzong's son Emperor Suzong, Li Huaiguang became a commander of Guo's guards. Sometime thereafter, he was made the discipline officer of the Shuofang army. During the meantime, for his accomplishments, he was also getting progressively greater honorary positions. It was said that as discipline officer, he was honest, hard-working, harsh, and fierce, and was willing to put people to death for their violation of military disciplines and did not spare his own friends and relatives. As Guo was himself lax toward his officers, he entrusted the matters of discipline to Li, and the army much feared Li.