The Congressional Record and Hearings often contain many speeches. Use the Advanced Search feature to limit your search to these documents. Advanced Search can also be used to search for a particular speaker.
This online archive from the University of California at Santa Barbara includes many sources on the American presidency--everything from the Public Papers of the Presidents to an audio/video archive of presidential speeches.
From the Miller Center at the University of Virginia, this site features texts of major speeches from every president. Also includes audio and video of more recent presidential speeches.
Contains material that was compiled and published by the Office of the Federal Register, National Archives and Records Administration. Includes Presidents George H.W. Bush to Obama.
Contains material that was compiled and published by the Office of the Federal Register, National Archives and Records Administration. Presidents Hoover to Clinton.