- IAWA Small Collections,, 1907/20133
- IAWA: International Archive of Women in Architecture Records, 1967/2013, bulk 1985/20081
- Ice Family Genealogy and Other Material, 1929/19321
- 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 Odd Fellows. St. Albans Lodge, No. 31 (St. Albans, Vt.) Minute Book, 1917/19322
- Independent Order of St. Luke Records, 1877/197012
- Industrial Education Association for Southern Mountaineers Collection,, 1930/19362
- Inge Horton Architectural Collection, 1964/1999111
- Ingleside Book Club Records, 1923/20231
- Institute for the History of Technology and Industrial Archaeology Records, 1875/2005, bulk 1980/200558
- 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
- Instructive Visiting Nurses Association records, 1902/199920
- Intercollegiate Athletics Records, 1930/2023, bulk 1975/20004