Samuel Kanyon Doe (6 May 1951 – 9 September 1990) was a Liberian politician who served as the Liberian leader from 1980 to 1990, first as a military leader and later as a civilian. While a master sergeant in the Armed Forces of Liberia (AFL), Doe staged a violent coup d'état in April 1980 that left him de facto head of state. During the coup, then-president William Tolbert and much of the True Whig Party leadership were executed. Doe then established the People's Redemption Council, assuming the rank of general.Doe suspended the constitution and headed the country's military junta for the next five years. In 1985, he ordered an election and officially became the 21st President of Liberia. The election was marked by controversy as there was evidence of election fraud. Doe had support from the United States; it was a strategic alliance due to his anti-Soviet stance taken during the years of the Cold War prior to the changes in 1989 that led to the dissolution of the Soviet Union.

The first native head of state in the country's history, Doe was a member of the Krahn ethnic group from the South Eastern region of Liberia. Before the 1980 coup, natives had often held a marginal role in society, which was dominated by the descendants of the Americo-Liberian Pioneers; composed primarily of free-born North American blacks and freed slaves, the Pioneers were the immigrants who had established Liberia in the 1820s and led the country beginning with independence in 1847.

Doe opened Liberian ports to Canadian, Chinese and European ships. This brought in considerable foreign investment from foreign shipping firms and earned Liberia a reputation as a tax haven.

Doe attempted to legitimize his regime with passage of a new constitution in 1984 and elections in 1985. However, opposition to his rule increased, especially after the 1985 elections, which were declared to be fraudulent by most foreign observers. For political reasons, the U.S. continued to support him. Thomas Quiwonkpa was murdered due to a failed coup.In the late 1980s, as the U.S. government adopted more fiscal austerity and the threat of Communism declined with the waning of the Cold War, the U.S. became disenchanted with the entrenched corruption of Doe's government and began cutting off critical foreign aid. This, combined with the popular anger generated by Doe's favoritism toward Krahns, placed him in a very precarious position.

A civil war began in December 1989, when rebels entered Liberia through Ivory Coast, capturing and overthrowing Doe on 9 September 1990. Doe was then tortured during interrogation and murdered by his captor, Prince Johnson, a one-time ally of Charles Taylor.