Ni Kuan 兒寬 (died 103 BCE; should be written 倪寬) was a high official during the mid-Former Han period 前漢 (206 BCE-8 CE) and an expert in hydraulic works.
He hailed from Qiancheng 千乘 (modern Gaoqing 高青, Shandong) and had studied the Confucian Classic Shangshu 尚書 "Book of Documents" by Master Ouyang 歐陽生. During the reign of Emperor Wu 漢武帝 (r. 141-87 BCE) he was made a scholar at the National University (taixue 太學) where he was a disciple of Kong Anguo 孔安國. He was appointed clerk of the Grand Astrologer (zhanggu 掌故) and literary clerk of the Chamberlain for Law Enforcement (tingwei wenxue zushi 廷尉文學卒史).
Ni was highly esteemed by Chamberlain Zhang Tang 張湯. When the latter was promoted to Censor-in-chief (yushi dafu 御史大夫). Ni Kuan was made attendant censor (shiyushi 侍御史). As an expert in the Classics he lectured to Emperor Wu about the Shangshu and was thereafter made Grand Master of the Palace (zhong dafu 中大夫).
In 133m he was appointed Left Chamberlain for the Capital (zuo neishi 左內史). He suggested to the emperor strengthening agriculture, sparingly use the penal law, survey law cases with caution and to promote persons of high competence. Ni advocated the construction of a canal in the territory of Zheng 鄭國 in order to enhance the irrigation of the whole region. This project was the Liupu Canal 六鋪渠. In 110 Ni Kuan was appointed Censor-in-chief.
Together with the historian Sima Qian 司馬遷 he calculated a new calendar, the Taichu Calendar 太初曆. Ni Kuan died in office.