Zhang Hongjing (simplified Chinese: 张弘靖; traditional Chinese: 張弘靖; pinyin: Zhāng Hóngjìng) (760 – July 24, 824), courtesy name Yuanli (元理), formally the Marquess of Gaoping (高平侯), was an official of the Tang dynasty of China, serving as a chancellor during the reign of Emperor Xianzong. He was blamed in traditional histories for misruling Lulong Circuit (盧龍, headquartered in modern Beijing), leading to Lulong soldiers' subsequent rebellion against the imperial government under Zhu Kerong.
Zhang Hongjing was born in 760, during the reign of Emperor Suzong. His family traced its ancestry to the Jin Dynasty official Zhang Hua. His grandfather Zhang Jiazhen had served as a chancellor during the reign of Emperor Suzong's father Emperor Xuanzong, and at the time of Zhang Hongjing's birth, Zhang Hongjing's father Zhang Yanshang was already serving in the imperial government. Zhang Hongjing himself was said to be elegant, lenient, faithful, and honest in his youth.
During the reign of Emperor Suzong's grandson Emperor Dezong, Zhang Yanshang was serving in progressively more important positions, and eventually served as a chancellor in 787 before dying late that year. Zhang Hongjing, on account of his heritage, was made an officer at Henan Municipality (河南, i.e., the region of the eastern capital Luoyang), and later served as the sheriff of Lantian County (藍田, in modern Xi'an, Shaanxi). When Du Ya (杜亞) served as the defender of Luoyang, he invited Zhang Hongjing to serve as his assistant. There was an occasion when the officer Linghu Yun (令狐運) had been chasing thugs out of the city that a robbery occurred in the same locale. As Linghu belonged to a strong clan, Du came to suspect Linghu of having committed the robbery and asked Zhang and his colleague Mu Yuan (穆員) to investigate. As both Mu and Zhang believed that Linghu would not commit such an act, they asked for the investigation to be suspended. Du refused to listen to them and had LInghu arrested; he also threw Mu and Zhang off his staff. However, a later investigation ordered by Emperor Dezong located the actual robber.