The President's Commission on the Assassination of President Kennedy, known unofficially as the Warren Commission, was established by PresidentLyndon B. Johnson through Executive Order11130 on November 29, 1963 to investigate the assassination of United States President John F. Kennedy that had taken place on November 22, 1963. The U.S. Congress passed Senate Joint Resolution 137 authorizing the Presidential appointed Commission to report on the assassination of President John F. Kennedy, mandating the attendance and testimony of witnesses and the production of evidence. Its 888-page final report was presented to President Johnson on September 24, 1964 and made public three days later. It concluded that President Kennedy was assassinated by Lee Harvey Oswald and that Oswald acted entirely alone. It also concluded that Jack Ruby acted alone when he killed Oswald two days later. The Commission's findings have proven controversial and have been both challenged and supported by later studies.
The Commission took its unofficial name—the Warren Commission—from its chairman, Chief JusticeEarl Warren. According to published transcripts of Johnson's presidential phone conversations, some major officials were opposed to forming such a commission and several commission members took part only reluctantly. One of their chief reservations was that a commission would ultimately create more controversy than consensus.
Nicholas Katzenbach has been named as providing advice after the assassination of John F. Kennedy that led to the creation of the Warren Commission. On November 28 he sent a memo to Johnson's White House aide Bill Moyers recommending the formation of a Presidential Commission to investigate the assassination. To combat speculation of a conspiracy, Katzenbach said that the results of the FBI's investigation should be made public. He wrote, in part: "The public must be satisfied that Oswald was the assassin; that he did not have confederates who are still at large".