Mao Zedong played a central role in leading the largest communist revolution in the world outside the Soviet Union and in the ‘creative developments’ or ‘Sinification’ of Marxist-Leninist orthodoxy to suit Chinese conditions. He combined the roles of Lenin and Stalin. The essay traces his rise to power in the Chinese Communist Party between the 1920s and 1949 and his career as leader of the People’s Republic of China from 1949 to 1976, looking at the part he played in key moments, including developments in the Yan’an base area from the late 1930s, the Great Leap Forward, and the Cultural Revolution. The essay examines the central ideas in Mao’s philosophy, such as the primacy of practice, contradiction, rectification, and concern with bureaucracy. It goes on to explore key debates in the historiography and asks what ‘Maoism’ really means. The personality cult around Chairman Mao culminated in outrageous veneration in the 1960s and his memory today elicits strong feelings, both positive and negative. Despite his many mistakes and towering cruelty, he is still widely respected in China, as can be seen from his appropriation in popular culture. His ideas continue to be influential in parts of Asia and Latin America and his image is still invoked by contending interests in China.