The Theodore Roosevelt Collection, housed in Harvard’s Houghton and Widener libraries, is a major resource for study of the life and times of the 26th president of the United States. The collection originated as a research library opened in New York City by the Roosevelt Memorial Association in 1923. It was presented by that organization (known since 1953 as the Theodore Roosevelt Association) to Harvard University, Roosevelt's alma mater, in 1943.

The collection includes correspondence of Roosevelt and his family, original manuscripts that include many of Roosevelt’s diaries, speeches, articles, and books, the archives of the Progressive Party and of many of Roosevelt’s biographers, along with a vast collection of books and articles, photographs, political cartoons, and ephemera relating to both Roosevelt’s personal and professional life.