- IAWA Small Collections,, 1907/20134
- IAWA: International Archive of Women in Architecture Records, 1967/2013, bulk 1985/20082
- Ignorance Club collection, 1908/20242
- Independent Order of Odd Fellows. Olean Lodge No. 471 (Olean, N.Y.) Records, 1920/1956, bulk 1920/19251
- Independent Order of St. Luke Records, 1877/197013
- Inge Horton Architectural Collection, 1964/1999106
- Ingeborg Hartmann Diary, 1939/19402
- Ingleside Book Club Records, 1923/20231
- Institute for the History of Technology and Industrial Archaeology Records, 1875/2005, bulk 1980/200562
- Institute for the History of Technology and Industrial Archaeology, Records regarding Blair Mountain, 1906/1992, bulk 1990/19921
- Institute of Inter-American Affairs Records, 1930/1939, bulk 1930/19391
- Institute on the Teaching of Latin Records, 1938/1980, bulk 1938/19802
- Instructive Visiting Nurses Association records, 1902/199923
- Intercollegiate Athletics Records, 1930/2023, bulk 1975/20004
- Intercollegiate Athletics records, 19202