Georgios Koumanakos (Greek: Γεώργιος Κουμανάκος) was a Greek Army officer and peace activist.
Born in Gytheio, Laconia in 1913, he fought in World War II, in the Greek Civil War against the Communists and commanded the Greek Expeditionary Force in Korea with disticntion. By 1967, he had reached the rank of Major General. As an opponent of the Greek military junta of 1967-1974, he was retired from the army and sent for three years into internal exile by the military regime.
After the junta's fall in 1974, he became chairman of the state-run Hellenic Telecommunications Organization and PYRKAL weapons industry.
In the 1980s, he was a well-known activist for nuclear disarmament and the withdrawal of US bases from Greece; along with 7 other high-ranking generals from NATO countries (includging Marshal Francisco da Costa Gomes and Brigadier Michael Harbottle) he co-signed the Generals for Peace and Disarmament initiative in 1981, and became a member of the Soviet-sponsored World Peace Council.