Lu Huaishen (盧懷慎) (died December 11, 716), formally Count Wencheng of Yuyang (魚陽文成伯), was an official of the Chinese dynasty Tang Dynasty and Wu Zetian's Zhou Dynasty, serving as a chancellor during the reign of Emperor Xuanzong. He was known for his honesty as an official, but was criticized both in his time and posterity for not making decisions of his own and simply yielding to his colleague Yao Chong.
It is not known when Lu Huaishen was born. He was from the "The third house of northern ancestry" (北祖第三房) of the prominent Lu clan of Fanyang. During Tang Dynasty, Lu Huaishen's grandfather Lu Zhe (盧悊) served as the magistrate of Lingchang County (靈昌, in modern Anyang, Henan), and thus relocated his family to Lingchang. Lu Huaishen's father Lu Ting (盧挺) served as an official at Tan Prefecture (roughly modern Changsha, Hunan).
Lu Huaishen was said to be highly intelligent as a child, and he impressed his father's friend, the imperial censor Han Siyan (韓思彥). It was said that he was careful with his behavior when he was young, and after he passed the imperial examinations, he served as Jiancha Yushi (監察御史), a low-level imperial censor, probably during Wu Zetian's reign.
In 705, Wu Zetian was overthrown in a coup, and her son Li Xian the Crown Prince, a former emperor, returned to the throne (as Emperor Zhongzong). His reign was one where the civil service system was heavily influenced by powerful individuals, and Lu Huaishen, who served as a chief deputy censor (御史中丞, Yushi Zhongcheng) during this time, made repeated petitions for civil service reforms, which Emperor Zhongzong did not accept. In 706, when Emperor Zhongzong sent officials to examine the 10 circuits the realm was divided into, Lu was one of the officials sent. Lu was eventually promoted to be Huangmen Shilang (黃門侍郎), the deputy head of the examination bureau of government (門下省, Menxia Sheng), and he was created the Count of Yuyang.