Zhu Jun (140s? - c.April 195), courtesy name Gongwei, was a military general and official who lived during the Eastern Han dynasty of China.

Zhu Jun was from Shangyu County (上虞縣), Kuaiji Commandery (會稽郡), which is present-day Shangyu District, Shaoxing, Zhejiang. His father died when he was still young, so he was raised by his mother, who earned a living by selling fabrics. When he reached adulthood, he served as a scribe in the local county office. Zhu Jun gained a reputation for being very filial towards his mother. Despite this, when an acquaintance Zhou Gui (周规) was unable to repay his debts to the local authorities, Zhu Jun stole fabrics from his mother in order to help Zhou settle the debts. As a result, Zhu Jun's mother lost her property. Greatly angered, she then blamed Zhu Jun. Zhu Jun replied, "Small losses will result in great fortunes later. To be poor first before becoming rich is the natural order." Du Shang (度尚; 117-166), the Chief of Shangyu County, favoured him and recommended him to serve in the commandery office under Wei Yi (韋毅), the Administrator of Kuaiji Commandery. Zhu Jun later became a Registrar (主簿) when Yin Duan (尹端) replaced Wei Yi as the Administrator. In 173, Yin Duan was impeached for his failure in quelling Xu Chang's rebellion. Initially, Yin's punishment was to be executed. However, Zhu Jun made his way to the capital and bribed the relevant officials; as a result, Yin's punishment was reduced. Yin was overjoyed upon knowing of his reduced punishment, but Zhu Jun never revealed his involvement to Yin.

Yin Duan's successor, Xu Gui (徐珪), further nominated Zhu Jun as a xiaolian (civil service candidate), after which the Han central government appointed Zhu Jun as the Prefect (令) of Lanling County (蘭陵縣).

In c.February 178, when a rebellion broke out in Jiaozhi Commandery in the far south, the Han imperial court appointed Zhu Jun as the Inspector (刺史) of Jiao Province and ordered him to suppress the revolt. Zhu Jun managed to rally some soldiers from his home commandery and gather another 5,000 soldiers from other commanderies to join him in fighting the rebels. He successfully quelled the rebellion and killed the rebel leader Liang Long (梁龍) in Nanhai Commandery (南海郡). In 181, he attacked and defeated Wuhuman (烏滸蠻), another rebel leader in Hepu (合浦) and Jiaozhi commanderies. In recognition of his achievements, the Han imperial court enfeoffed him as a Marquis of a Chief Village (都亭侯) and summoned him to the imperial capital Luoyang to serve as a Counsellor Remonstrant (諫議大夫).

In 184, when the Yellow Turban Rebellion broke out, the Han imperial court appointed Zhu Jun as Right General of the Household (右中郎將) and ordered him, Lu Zhi and Huangfu Song to lead imperial forces to eliminate the rebels. Zhu Jun defeated the rebels at Changshe (長社) with the aid of Huangfu Song and Cao Cao. He was elevated from a village marquis to a district marquis under the title "Marquis of Xi District" (西鄉侯) and was promoted to General of the Household Who Suppresses Rebels (鎮賊中郎將). Zhu Jun and Huangfu Song later joined forces to defeat the rebels at Yangzhai (陽翟) and Xihua (西華) counties and pacified Yu Province. Later, Zhu Jun led his troops south to Nanyang Commandery (南陽郡) and joined the local government forces there in defeating the Yellow Turban rebels led by Zhao Hong (趙弘) and later Han Zhong (韓忠). In early 185, he defeated another group of rebels led by Sun Xia (孫夏) and succeeded in restoring peace in Nanyang Commandery.

In 185, the Han imperial court promoted Zhu Jun to Right General of Chariots and Cavalry (右車騎將軍) and elevated him to a county marquis under the title "Marquis of Qiantang" (錢唐侯). However, after his mother died, he resigned and returned home to perform filial mourning. After the mourning period, he returned to serve as Court Architect (將作大匠) and was subsequently reassigned to be Minister Steward (少府) and Minister Coachman (太僕). In the late 180s, when the Heishan bandits led by Zhang Yan raided Henei Commandery (河內郡) and threatened Luoyang, the Han central government appointed Zhu Jun as the Administrator (太守) of Henei Commandery and ordered him to lead troops to attack the bandits. Zhu Jun subsequently held the following appointments: Household Counsellor (光祿大夫), Colonel of the City Gates (城門校尉) and Intendant of Henan (河南尹).

In 189, the warlord Dong Zhuo took advantage of the political vacuum created in the aftermath of Emperor Ling's death to seize control of, and dominate the Han central government. He felt rather intimidated by Zhu Jun because of the latter's standing in the imperial court as a veteran general and senior official. In 190, when a coalition of warlords launched a campaign against Dong Zhuo in the name of freeing the central government and Emperor Xian from his control, Dong Zhuo became afraid and wanted to relocate the imperial capital from Luoyang to Chang'an in the west. Zhu Jun strongly objected, but Dong Zhuo pushed his plan through. Although he dreaded Zhu Jun and wanted to eliminate him, he still appointed Zhu Jun as Minister Coachman (太僕) in Emperor Xian's name. Zhu Jun rejected the appointment.

After Dong Zhuo left for Chang'an with Emperor Xian, the emperor's subjects and Luoyang's residents, Zhu Jun remained in Luoyang and maintained contact with the anti-Dong Zhuo coalition. However, he feared that Dong Zhuo would turn back and attack him, so he abandoned his post and fled south to Jing Province. Dong Zhuo then appointed Yang Yi (楊懿) as the Intendant of Henan to guard Luoyang. When Zhu Jun heard about it, he led troops from Jing Province to attack Luoyang and drive away Yang Yi. At the time, much of Luoyang had been burnt down when Dong Zhuo gave orders to relocate the imperial capital to Chang'an, so Zhu Jun moved to a garrison at Zhongmu County (中牟縣).