Zheng Zhong 鄭眾 (d. 83 CE), courtesy name Zhongshi 仲師, was an official and Confucian scholar of the Later Han period 後漢 (25-220 CE). In order to discern him from the great philosopher Zheng Xuan 鄭玄, the "Later Zheng" (Hou Zheng 後鄭), he was called the "Earlier Zheng" (Xian Zheng 先鄭).
He hailed from Kaifeng 開封 (modern Kaifeng, Henan) and was the son of Zheng Xing 鄭興 (who is also meant with the designation "Earlier Zheng"), an expert in the canonic commentaries to the Confucian Classic Chunqiu 春秋 "Spring and Autumn Annals". Zheng Zhong himself compiled notes to this Classis, the Chunqiu nanji tiaoli 春秋難記條例 and Chunqiu shan 春秋刪 and enhanced his expertise by studies of the Yijing 易經 "Book of Changes" and Shijing 詩經 "Book of Songs". Under Emperor Ming 漢明帝 (r. 57-75 CE) he was appointed palace steward (jishizhong 給事中) and then commandant of cavalry (yueji sima 越騎司馬).
In this position he participated in the first campaigns of the Later Han dynasty against the steppe federation of the Northern Xiongnu 北匈奴, and so much impressed the barbarians that their envoys to the Han court spoke in admiring words of him. Zheng Zhong's political position to destroy the steppe peoples was at that time disliked at the court, so that he was dismissed. Later on he managed to rise to the post of Cavalry commander of the army (jun sima 軍司馬).
In the next expedition to the west, he liberated the former commandery (jun 郡) of Dunhuang 敦煌 and was therefore appointed Leader of the court gentlemen (zhonglangjiang 中郞將) and entrusted with the preparation of further conquest. Zheng Zhong then rose to the civilian post of governor (taishou 太守) of the commandery of Wuwei 武威, later of Zuofengyi 左馮翊. His great record of success made Zheng Zhong eligible as successor of Chamberlain for the national treasury (dasinong 大司農) Deng Biao 鄧彪 in 81 CE. Zheng was therefore also known by the name "Treasury Chamberlain Zheng" (Zheng Sinong 鄭司農).
He was opposed to the reintroduction of the government monopoly on the production and sales of salt and iron. Zheng Zhong died in office. Of his writings, only fragments survive that are found in the collection Yuhanshanfang jiyi shu 玉函山房輯佚書: Zhouyi Zheng Sinong zhu 周易鄭司農注, Maoshi Xian Zheng yi 毛詩先鄭義, Zhouli Zheng Sinong jiegu 周禮鄭司農解詁, Zhengshi hunli 鄭氏婚禮, Chunqiu dieli zhangju 春秋牒例章句, and Guoyu zhangju 國語章句.