Juche, officially the Juche idea, is a component of Kimilsungism–Kimjongilism, the state ideology of North Korea and the official ideology of the Workers' Party of Korea. North Korean sources attribute its conceptualization to Kim Il Sung, the country's founder and first leader. Juche was originally regarded as a variant of Marxism–Leninism until Kim Jong Il, Kim Il Sung's son and successor, declared it a distinct ideology in the 1970s. Kim Jong Il further developed Juche in the 1980s and 1990s by making ideological breaks from Marxism–Leninism and increasing the importance of his father's ideas. Juche incorporates the historical materialist ideas of Marxism–Leninism but also strongly emphasizes the individual, the nation state, and national sovereignty. Juche posits that a country will prosper once it has become self-reliant by achieving political, economic, and military independence. As Kim Jong Il emerged as Kim Il Sung's likely successor in the 1970s, loyalty to the leader was increasingly emphasized as an essential part of Juche, as expressed in the Ten Principles for the Establishment of a Monolithic Ideological System.

Juche has been variously described by critics as a quasi-religion, a nationalist or fascistic ideology, and a deviation from Marxism–Leninism.

Juche comes from the Sino-Japanese word 主體 (shinjitai: 主体), whose Japanese reading is shutai. The word was coined in 1887 to translate the concept of Subjekt in German philosophy (subject, meaning "the entity perceiving or acting upon an object or environment") into Japanese. The word migrated to the Korean language at around the turn of the century and retained this meaning. Shutai went on to appear in Japanese translations of Karl Marx's writings. North Korean editions of Marx used the word Juche even before the word was attributed to Kim Il Sung in its supposedly novel meaning in 1955.

In contemporary political discourse on North Korea, Juche has a connotation of "self-reliance", "autonomy", and "independence". It is often defined in opposition to the Korean concept of Sadae, or reliance on the great powers. South Koreans use the word without reference to the North Korean ideology.

The ideology is officially known as Juche sasang (주체사상) in Korean and the Juche idea in English. Juche sasang literally means "subject idea" and has also been translated less commonly as Juche thought or Jucheism. Adherents of Juche are sometimes referred to as "Jucheists".

Official statements by the North Korean government attribute the origin of Juche to Kim Il Sung's experiences in the Down-with-Imperialism Union during Korea's liberation struggle against Japan. However, the first documented reference to Juche as an ideology dates to 1955, when Kim Il Sung delivered a speech titled "On Eliminating Dogmatism and Formalism and Establishing Juche in Ideological Work." The speech promoted a political purge similar to the Yan'an Rectification Movement in China. It became known as the "Juche speech" and is considered one of Kim Il Sung's most important works.

Western scholars generally agree that Hwang Jang-yop, Kim Il Sung's top adviser on philosophy, was responsible for the conceptualization and early development of Juche. Hwang rediscovered the Juche speech sometime in the late 1950s, when Kim Il Sung, having established a cult of personality, sought to develop his own version of Marxism–Leninism and solidify his position in the Workers' Party of Korea (WPK). Hwang expanded upon the meaning of Juche and rewrote Korean communist history to make it appear as though Kim Il Sung had been the WPK's leader since its inception. Andrei Lankov, a Russian scholar of Korean studies, argues that the first reference to Juche as an ideology was on 14 April 1965, when Kim Il Sung gave a speech in Indonesia titled "On Socialist Construction in the Democratic People's Republic of Korea and the South Korean Revolution" (조선민주주의인민공화국에서의사회주의건설과남조선혁명에대하여). Lankov posits that the 1955 speech "used the word in a different meaning" and that Juche was adopted as the "basic ideological principle of North Korean politics" only after the 1965 speech.

On the Juche Idea, the principal work on Juche, was published under Kim Jong Il's name in 1982. In North Korea it serves as "the authoritative and comprehensive explanation of Juche." According to the treatise, the WPK is responsible for educating the masses in the ways of Juche thinking. Juche is inexorably linked with Kim Il Sung and "represents the guiding idea of the Korean revolution". Although Juche is rooted in Marxism–Leninism, it is not merely a creative application of the ideas of Marx and Lenin to Korean conditions. Rather, it is a "new phase of revolutionary theory" and represents "a new era in the development of human history". Kim Jong Il also criticized the Korean communists and nationalists of the 1920s for their "elitist posture", saying they were "divorced from the masses".