A Preliminary Analysis of the October 1, 1965, Coup in Indonesia, more commonly known as the "Cornell Paper", is an academic publication detailing the events of an abortive coup d'état attempt by the self-proclaimed September 30 Movement, produced on January 10, 1966. The study was written by Benedict Anderson and Ruth McVey, with the help of Frederick Bunnell, using information from various Indonesian news sources. At the time of writing, the three were members of Cornell University's network of graduate students and scholars on Southeast Asia.

The Thirtieth of September Movement was a self-proclaimed organization of Indonesian National Armed Forces members. In the early hours of 1 October 1965, they assassinated six Indonesian Army generals in an abortive coup d'état. Later that morning, the organisation declared that it was in control of media and communication outlets and had taken President Sukarno under its protection. By the end of the day, the coup attempt had failed in Jakarta. Meanwhile, in central Java there was an attempt to take control over an army division and several cities. By the time this rebellion was put down, two more senior officers were dead.