The Great Leap Forward was an industrialization campaign within China from 1958 to 1962, led by the Chinese Communist Party (CCP). CCP Chairman Mao Zedong launched the campaign to transform the country from an agrarian society into an industrialized society through the formation of people's communes. The Great Leap Forward is estimated to have led to between 15 and 55 million deaths in mainland China during the 1959–1961 Great Chinese Famine it caused, making it the largest or second-largest famine in human history.

The Great Leap Forward stemmed from multiple factors, including "the purge of intellectuals, the surge of less-educated radicals, the need to find new ways to generate domestic capital, rising enthusiasm about the potential results mass mobilization might produce, and reaction against the sociopolitical results of the Soviet Union's development strategy." Mao ambitiously sought an increase in rural grain production and an increase in industrial activity. Mao was dismissive of technical experts and basic economic principles, which meant that industrialization of the countryside would solely be dependent on the peasants. Grain quotas were introduced with the idea of having peasants provide grains for themselves and support urban areas. Output from the industrial activities such as steel was also supposed to be used for urban growth. Local officials were fearful of the Anti-Right Deviation Struggle and they competed to fulfill or over-fulfill quotas which were based on Mao's exaggerated claims, collecting non-existent "surpluses" and leaving farmers to starve to death. Higher officials did not dare to report the economic disaster which was being caused by these policies, and national officials, blaming bad weather for the decline in food output, took little or no action.

The major changes which occurred in the lives of rural Chinese people included the incremental introduction of mandatory agricultural collectivization. Private farming was prohibited, and those people who engaged in it were persecuted and labeled counter-revolutionaries. Restrictions on rural people were enforced with public struggle sessions and social pressure, and forced labor was also exacted on people. Rural industrialization, while officially a priority of the campaign, saw "its development ... aborted by the mistakes of the Great Leap Forward". Economist Dwight Perkins argues that "enormous amounts of investment only produced modest increases in production or none at all. ... In short, the Great Leap [Forward] was a very expensive disaster".

The CCP studied the damage that was done at various conferences from 1960 to 1962, especially at the Seven Thousand Cadres Conference in 1962, during which Mao Zedong ceded day-to-day leadership to pragmatic moderates like Chinese President Liu Shaoqi and Vice Premier Deng Xiaoping. Acknowledging responsibilities for the Great Leap Forward, Mao did not retreat from his policies; instead, he blamed problems on bad implementation and "rightists" who opposed him. He initiated the Socialist Education Movement in 1963 and the Cultural Revolution in 1966 in order to remove opposition and re-consolidate his power. In addition, dozens of dams constructed in Zhumadian, Henan, during the Great Leap Forward collapsed in 1975 (under the influence of Typhoon Nina) and resulted in the 1975 Banqiao Dam failure, with estimates of its death toll ranging from tens of thousands to 240,000.

The core goal of the Great Leap Forward was to increase industrial and agricultural outputs by using mass mobilization to raise labor inputs and therefore overcome China's lack of material, technological and monetary inputs. The Great Leap Forward also sought to address imbalances between rural China and urban China existed in the prerevolutionary period and continued into the 1950s.

Classical Marxist theory hypothesized a relatively linear progression of development and a worldwide revolution beginning with the most developed countries. At the founding of the People's Republic of China in 1949, the country was one of the poorest in the world. The Great Leap Forward attempted to defy the conventional understanding of the time required for economic development. Through rapid industrialization, it aimed to close the gap between China's developmental stage and its political aspirations. In March 1955, at a national conference of the Party, Mao declared that China "would catch up with and surpass the most powerful capitalist countries in several dozen years", and in October, Mao announced that he would complete the building of a socialist state in 15 years.

In the late 1950s, China's socio-political landscape experienced significant rural reforms and the aftermath of previous policies aimed at collectivization rather than individualism. Before the Great Leap Forward, the Chinese government initiated land reforms that redistributed land from landlords to peasants, but these reforms still needed to attain the expected agricultural productivity. The early 1950s saw the establishment of agricultural cooperatives, yet these changes brought mixed outcomes. However, the push towards rapid industrialization and the establishment of people's communes in rural areas were central to the Great Leap Forward, reflecting the government's belief that collectivization and large-scale projects would boost agricultural and industrial outputs. The communes were meant to centralize farming and labor, supposedly leading to increased efficiency and output; still, in reality, and practice, these measures often disrupted traditional farming practices and led to decreased productivity. Dali Yang stated, "The initial stages of collectivization brought chaos and inefficiency, with agricultural productivity often declining".

By the time of the Great Leap Forward, increased Sino-Soviet tensions meant that China could not depend on Soviet technological assistance. Mao emphasized China's self-reliance in technology and industry and discouraged reliance on foreign technology.