Sukarno or Soekarno ( soo-KAR-noh, Indonesian: [suˈkarno]; born Koesno Sosrodihardjo, Javanese: [ˈkʊsnɔ]; 6 June 1901 – 21 June 1970) was an Indonesian statesman, orator, revolutionary, and nationalist who was the first president of Indonesia, serving from 1945 to 1967.

Sukarno was the leader of the Indonesian struggle for independence from the Dutch colonialists. He was a prominent leader of Indonesia's nationalist movement during the colonial period and spent over a decade under Dutch detention until released by the invading Japanese forces in World War II. Sukarno and his fellow nationalists collaborated to garner support for the Japanese war effort from the population, in exchange for Japanese aid in spreading nationalist ideas. Upon Japanese surrender, Sukarno and Mohammad Hatta declared Indonesian independence on 17 August 1945, and Sukarno was appointed president. He led the Indonesian resistance to Dutch re-colonisation efforts via diplomatic and military means until the Dutch recognition of Indonesian independence in 1949.

After a chaotic period of parliamentary democracy, Sukarno established an autocratic system called "Guided Democracy" in 1959 that successfully ended the instability and rebellions which were threatening the survival of the diverse and fractious country. In the early 1960s Sukarno embarked on a series of aggressive foreign policies under the rubric of anti-imperialism and personally championed the Non-Aligned Movement. These developments led to increasing friction with the West and closer relations with the USSR. After the events surrounding the 30 September Movement of 1965, the military general Suharto largely took control of the country in a Western-backed military overthrow of the Sukarno-led government. This was followed by repression of real and perceived leftists, including executions of Communist party members and suspected sympathisers in several massacres with support from the CIA and British intelligence services, resulting in an estimated 500,000 to over 1,000,000 deaths. In 1967, Suharto officially assumed the presidency, replacing Sukarno, who remained under house arrest until his death in 1970.