The Saur Revolution or Sowr Revolution (Pashto: د ثور انقلاب; Dari: إنقلاب ثور), also known as the April Revolution or the April Coup, was staged on 27–28 April 1978 (۷ ثور, lit. '7th Saur') by the People's Democratic Party of Afghanistan (PDPA) and overthrew Afghan president Mohammed Daoud Khan, who had himself taken power in the 1973 Afghan coup d'état and established an autocratic one-party system in the country. Daoud and most of his family were executed at the Arg in the capital city of Kabul by PDPA-affiliated military officers, after which his supporters were also purged and killed. The successful PDPA uprising resulted in the creation of a socialist Afghan government that was closely aligned with the Soviet Union, with Nur Muhammad Taraki serving as the PDPA's General Secretary of the Revolutionary Council. Saur or Sowr is the Dari-language name for the second month of the Solar Hijri calendar, during which the events took place.

The uprising was ordered by PDPA member Hafizullah Amin, who would become a significant figure in the revolutionary Afghan government. At a press conference in New York in June 1978, Amin claimed that the event was not a coup d'état, but rather a "popular revolution" carried out by the "will of the people" against Daoud's government. The Saur Revolution involved heavy fighting throughout Afghanistan and resulted in the deaths of as many as 2,000 military personnel and civilians combined; it remains a significant event in Afghanistan's history as it marked the beginning of decades of continuous conflict in the country.