Pythagoras Papastamatiou (Greek: Πυθαγόρας Παπασταματίου, 12 April 1930 – November 12, 1979), mainly known by the mononym Pythagoras, was a Greek lyricist and playwright.
In 1940 (during the outbreak of World War II), Pythagoras started attending high school at Agrinio All-male High school. During the German occupation of Greece, he was hiding in Valtos. In 1944, he joined ELAS. He graduated from high school after the end of the war.
In 1945, he moved to Athens. He attended the Drama School of the Athens Conservatory, where he was a student of Dimitris Rontiris. He later worked for sometime in theatre, and later, in 1958, he became a playwright. In 1973, he became an irregular member of the Greek Playwrights Club. In 1974, he became an associate member and, in 1975, a regular member of that club.