Zhang Juzheng (26 May 1525 – 9 July 1582) was a prominent grand secretary during the reigns of Ming emperors Longqing and Wanli. In 1547, he passed the highest level of official examinations and was granted the rank of jinshi. He then served at the Hanlin Academy. In 1567, the Longqing Emperor appointed him as grand secretary, and upon the ascension of the Wanli Emperor in 1572, he became the head of the grand secretaries.

During the early years of the reign of the Wanli Emperor, Zhang played a key role in centralizing the administration, limiting various privileges, and revising land tax exemptions. His decisive foreign and economic policies contributed to one of the most successful periods in Ming history. After his death in 1582, many of these reforms were reversed, and in 1584 his family was stripped of its accumulated property and wealth. He was not rehabilitated until more than half a century later, shortly before the fall of the Ming dynasty.

Zhang Juzheng was born in 1525 in Jiangling (present-day Jingzhou, Hubei). He studied Confucianism and successfully passed the provincial examination in 1540, but he failed the metropolitan examination in 1544. Three years later, at an unusually young age, he passed the metropolitan examination and also passed the palace examination, receiving the rank of jinshi. He then joined the Hanlin Academy. In 1554, he resigned due to illness. After six years, he returned to service, this time at the Guozijian (or Imperial University), and later at the Hanlin Academy. He never held office outside of Beijing.

In 1567, the Jiajing Emperor died. The senior grand secretary at the time, Xu Jie, had supported Zhang Juzheng's career since the late 1540s. He enlisted Zhang, then a Hanlin academic, to draft the Jiajing Emperor's final edict. This edict was published the day after the Emperor's death and orchestrated the accession of the Emperor's son, the Longqing Emperor, to the throne. Soon after, Zhang was promoted to grand secretary. During the Longqing Emperor's reign, Zhang's influence continued to grow. In 1572, shortly after the Longqing Emperor's death and the accession of his son, the Wanli Emperor, to the throne, the eunuch Feng Bao, head of the Directorate of Ceremonial (司禮監太監; Silijian taijian), worked with Zhang to depose the then senior grand secretary, Gao Gong. The pretext for this was Gao Gong's disrespectful remark to the Emperor. As a result, Zhang Juzheng became the head of the Grand Secretariat.

Zhang held onto his position of power for a decade until his death in 1582, during which he served as the Wanli Emperor's mentor and de facto ruler of China due to the Emperor's immaturity. During his time in office, he relied heavily on the support of eunuchs, particularly Feng Bao, and the Emperor's mother, Empress Dowager Li, who acted as regent. This allowed him to personally select his colleagues in the Grand Secretariat; he also exerted informal control over the Ministry of Rites and the Censorate, appointing his followers to important positions in both central offices and regional areas. These individuals were typically ambitious and driven. Through these tactics, Zhang gained significant influence in the government, despite lacking the authority to give orders or make demands due to his position. Instead, he could only issue orders or instructions in the name of the Emperor or informally.

Zhang sought to consolidate the power of the central government and elevate the role of the Emperor by streamlining the administration and bolstering the military, often at the expense of local interests. He wielded his influence in the Censorate to enforce stricter discipline within the bureaucracy, redirecting their focus from internal conflicts to tasks such as tax collection and suppression of bandits. To assess the effectiveness of the administration, monthly and semi-annual reports were compiled for each county and prefecture, measuring their success in these areas. This led to a period of peak efficiency in the Ming state administration from 1572 to 1582, a level typically only seen in the early years of the empire.

In contrast to the focus on internal self-improvement advocated by the followers of Wang Yangming's teachings, Zhang presented an alternative program based on pragmatic pursuit of the state's interests. He believed that actions aimed at the good of the state and its people were the correct course of action. His motto was "If it is to the benefit of the state, I would do it regardless of life or death".

Zhang presented his reforms as a return to the state at the beginning of the dynasty, positioning himself advantageously by citing the laws and decrees of the Ming dynasty's founder, the Hongwu Emperor, as an unassailable source of law. In general, Zhang advocated for the idea that more recent emperors and governments, particularly the Hongwu Emperor, should be seen as political models rather than the wise rulers of antiquity. He even brought up this topic at the metropolitan examinations of 1571, where he served as the chief examiner. Zhang justified his actions against intellectuals who were preoccupied with debates about morality and introspection by claiming that he was defending the interests of the empire rather than seeking personal gain. He viewed these individuals not as moral role models, but as irresponsible slackers, and thus attempted to suppress government-uncontrolled discussion gatherings of opposition-minded educated people. Wang Yangming's followers responded with resistance, seizing every opportunity to criticize Zhang's rule.