The Wuhan incident (Chinese: 七二零事件; pinyin: Qī èrlíng shìjiàn; lit. 'July 20th Incident') was an armed conflict in the People's Republic of China between two hostile groups who were fighting for control over the city of Wuhan in July 1967, at the height of the Cultural Revolution.

The two opposing groups were the conservative "Million Heroes" (Chinese: 百万雄师; pinyin: Bǎi wàn xióngshī) and the more radical "Wuhan Workers' General Headquarters" (Chinese: 工人总部; pinyin: Gōngrén zǒngbù). The former, numbering about 500,000 people, comprised mainly skilled workers, state and local party employees, and were supported by the local People's Liberation Army forces, led by the commander of Wuhan Military Region, General Chen Zaidao. The "Wuhan Workers' General Headquarters", also numbering close to 500,000 people, comprised mostly workers and students from Red Guard organizations and whose leaders had been in prison since the February Countercurrent.

Both sides engaged in an extensive propaganda war in an attempt to enlist proletarian grassroots support. Central authorities in Beijing eventually endorsed the Worker's Headquarters faction as the "true" revolutionary group and reprimanded Chen Zaidao for his military support to Million Heroes. The event was considered a pivotal turning point in the Cultural Revolution: it marked the first time military leaders refused to carry out orders given by the central authorities and the Cultural Revolution Group in particular. Fears of a more widespread PLA revolt led Mao and his core associates to scale back the movement's most radical components.

All over China during the Cultural Revolution, provincial and municipal governments were replaced by organizations known as Revolutionary Committees (alliances of cadres, soldiers and student/worker groups) to take charge of governing the country and cleansing it from "counterrevolutionary forces" and "reactionary elements". With orders from the top leadership to "find and capture those in power walking the capitalist road," almost all incumbent party and government officials became vulnerable to attacks from Red Guard organizations - not owing to their ideological disposition but solely as a result of their incumbency. However, "capitalist roader" was a nebulous label that could be liberally applied to anyone perceived to be counter to the revolutionary spirit. Various mass organizations around the country took advantage of this chaotic backdrop and seized the opportunity to overthrow incumbent power figures with whom they may have carried other, unrelated grievances. In the central industrial city of Wuhan, two groups largely coalesced around those who wanted to preserve the incumbent political order in the city and those who wanted to overthrow it.

The Workers' Headquarters arose out of a union of local Red Guard youth and various "revolutionary" workers organizations from Wuhan's numerous steel plants. On January 27, 1967, they attempted to lay siege to the Wuhan party organization and the municipal government and then seize power in the city themselves, much in the fashion of the Shanghai People's Commune. However, incumbent interests rallied ordinary residents against the action and the takeover ultimately failed. It was thereafter branded as a "counterrevolutionary incident". In February, more than 1000 radicals were detained, some of whom were imprisoned while others were released after making public confessions.

In March 1967, local PLA units under the command of General Chen Zaidao forcefully disbanded the Worker's Headquarters faction and detained some 500 of its leaders. At the same time, it had been funding its own "revolutionary mass organization", dubbed "The Million Heroes," drawn from a wider cross-section of conservative interests in the city. The Million Heroes, whose slogans were also broadly "revolutionary" in tone, were mainly intent on maintaining the status quo. Their position was that, in essence, the existing Wuhan political establishment was loyally adhering to the Cultural Revolution's main programme and therefore should not have been a target for struggle.

Central authorities in Beijing did not issue any public statements on the March 1967 actions taken by the PLA against the Workers' Headquarters faction; privately the Cultural Revolution Group (CRG) griped about the direction of the movement in Wuhan, but stopped short of issuing a rebuke to Wuhan's PLA leaders. Instead, they attempted to pull Chen Zaidao aside from a top-level military conference in Beijing in April and prod him into admitting that some of the March actions had gone too far and acknowledge that the local PLA may have made "mistakes" in their handling of the situation. Chen, however, refused to stand down, and insisted on the general correctness of the PLA's actions.

Tensions grew in Wuhan through April as the Worker's Headquarters faction carried out hunger strikes and conducted rallies, claiming to be the "true bearer" of the revolutionary cause; meanwhile, the Million Heroes accused the Worker's Headquarters of subverting the revolution by not properly adhering to the campaign to denounce Liu Shaoqi and Deng Xiaoping. Amid the growing hostilities, the CRG felt a greater urgency to respond and extend its 'divine interpretation' of the events on the ground. Under the auspice of Zhou Enlai and with approval from Mao, the authorities in Beijing issued an order to Chen to withdraw support to the Million Heroes. The directive asserted that the Wuhan military had made a mistake in "general orientation" in carrying out Cultural Revolution policies - that it must publicly admit that its March actions against Workers' Headquarters were incorrect. The directive also labelled the Million Heroes as a "conservative organization" and branded the Workers' Headquarters as a "revolutionary organization"; this was, in effect, the CRG throwing its weight behind the latter.