Mao Zedong (December 26, 1893 – September 9, 1976; Mao Tse-tung in Wade-Giles) was the chairman of the Politburo of the Communist Party of China from 1943 and the chairman of the Central Committee of the Communist Party of China from 1945 until his death. Throughout his leadership, the CCP (Chinese Communist Party) became the ruling party of mainland China as the result of its victory in the Chinese Civil War. On October 1, 1949, Mao declared the formation of the People's Republic of China at Tiananmen Square.

While in power, he started a series of experiments aimed at speeding up China's economic development known as the Great Leap Forward. He forged but later split an alliance with the Soviet Union and launched the Cultural Revolution.

Mao is widely credited for creating a mostly unified China free of foreign domination for the first time since the Opium Wars. However, critics point out that Mao's inappropriate economic policies in conjunction with the Three Years of Natural Disasters caused the famine of 1959–1961, which led to the deaths of millions of Chinese. Mao has also been criticized for his contribution to the split with the USSR, his establishment of a one-party dictatorship, and initiating the internal turmoil during the Cultural Revolution.

Mao Zedong is still sometimes referred to as Chairman Mao (毛主席). At the height of his personality cult, Mao was commonly known in China as the "Four Greats": "Great Teacher, Great Leader, Great Supreme Commander, Great Helmsman".