Qi, or Ch'i[1] in Wade–Giles romanization, was a regional state of the Zhou dynasty in ancient China, whose rulers held titles of Hou (侯), then Gong, before declaring themselves independent Kings.

Its first monarch was Jiang Ziya (Lord Tai; r. 1046–1015 BCE ), minister of King Wen and a legendary figure in Chinese culture.

Following the Zhou victory, the lands comprising much of the Shandong peninsula and some nearby surrounds were established as the state of Qi, with Jiang charged with ruling and defending them.

The Shang prince Wu Geng had joined the revolt along with the Dongyi polities of Yan [zh], Xu, and Pugu, located within the boundaries of Qi.

These were suppressed by 1039 BCE, but the Bamboo Annals suggest that the native people of Pugu continued to revolt for about another decade before being destroyed a second time c. 1026.

Guan Zhong's administrative reforms also included state monopolies on salt and iron, and in general were characteristic of the later political philosophy of Legalism.

[4]: 526 In 667 BCE, the lords of Qi, Lu, Song, Chen, and Zheng assembled in one of the first great interstate conferences, and Duke Huan was elected as their leader.

Using this authority, during the first eleven years of his hegemony, Duke Huan intervened in a power struggle in Lu; protected Yan from encroaching Western Rong nomads; drove off Northern Di nomads after their invasions of Wey and Xing, providing the people with provisions and protective garrison units; and led an alliance of eight states to conquer Cai and thereby block the northward expansion of Chu.

[7] After Duke Huan's death, a war of succession between rival claimants greatly weakened Qi and ending its reign of hegemony.

Once their battle formations are thrown into disarray, the central column should be in position to attack and victory will follow.While visiting Qi, Confucius was deeply impressed with perfection of performance of Shao music (韶) therein.

[8] During the Warring States period, Qi was famous for Linzi's Jixia Academy, where renowned scholars of the era from all over China would visit.

Modern scholarship understands the Jixia Academy not to be a physical institution, but an informal collaboration of sponsored scholars engaged in intellectual work.

[12] The wall stretches from Guangli village of today's Changqing District, Jinan, running across the mountain ridges of central Shandong Province to the Yellow Sea in the present-day city of Qingdao.

Qi is represented by the star Chi Capricorni in the "Twelve States" asterism in the "Girl" lunar mansion in the "Black Turtle" symbol.