Waldo Gifford Leland (July 17, 1879, in Newton, Massachusetts – October 19, 1966) was an American historian and archivist whose work for the Carnegie Institution and the Library of Congress was instrumental in the founding of the National Archives. He also served in leadership roles in a variety of historical and archival societies, including the American Council of Learned Societies, Society of American Archivists, National Park Service, and the FDR Library.