- Ignatieff, Vladimir,
- Ignatijeva, Ekaterina I.
- Ignatius, Saint, Bishop of Antioch, approximately 110
- Ignatova-Ivanova, Tsveteslava
- Ignatti, Ana Cristina
- Ignoffo, Carlo Michael
- Igo, C. W., Mrs.
- Igo, Marguerite.
- Iguchi, Akira
- Iguchi, Taisen
- Iguchis, Akira
- IGY World Data Center A--Oceanography.
- Iha, Danilo S.
- Ihára, Lúcio Tshuyoki
- Ihara, Yoh
- Iharlegui, Laura
- Ihering, H. von (Hermann), 1850-1930
- Ihering, Rodolpho von, 1883-1939
- Ihl, Thomas
- Ihle, J. E. W. (Johan Egbert Willem), 1879-1956
- Ihle, Kate
- Ihlenfeldt, Hans-Dieter
- Ihli, Carl Bolton.
- Ihlow, Flora
- Ihrig, Herbert G.
- Ihssen, Georg
- Ihssen, Peter E.
- Iiabtekt, Ernst
- Iida, Shigeo
- Iida, Taichi
- Iigo, Masayuki
- Iijima, Isao, 1861-1921
- Iijima, Kai.
- Iino, Teruhiko
- Iizuka, Akira
- Iizuka, Yoshiyuki
- IJland, Steven
- Ijzereef, Gerard Frans
- Ikabanga, Davy U.
- Ikagawa, Raine
- Ikai, Sanzaemon.
- Ikata, Takaaki
- Ikawa, Haruyoshi
- Ike Hawkersmith Nursery,
- Ikebe, Chiho
- Ikebe, Chikako
- Ikeda, Andrea Kyoko
- Ikeda, Eisen, 1790-1848
- Ikeda, H
- Ikeda, Hiroshi
- Ikeda, Iwaji
- Ikeda, Koson, 1802?-1867?
- Ikeda, Mark
- Ikeda, S
- Ikeda, Tetsuya
- Ikeda, Tomochika.
- Ikeda, Y
- Ikeda, Yoshimine
- Ikegami, Susumu
- Ikehara, Isaac I
- Ikehara, Walter
- Ikejiri, Takehito.
- Iken, Katrin
- Ikenaga, Hiroshi
- Ikeno, Seiichirō, 1866-1943
- Ikenobō, Senjō, 1769-1832
- Ikenobō, Senmyō, 1793-1864
- Iker, Sam.
- Ikerd, Harold
- Ikeya, Noriyuki
- Ikonga, Jérôme Mokoko
- Ikyaagba, Emmanuel
- Ilagan, Jose M.
- Ilan, Micha
- Ilangakoon, Anoukchika D
- Ilango, K
- Ilarri, Martina Di Iulio
- Ilayperuma, Isurani
- Ildrewe, Miss.
- Iles, David T.
- Iles, Dudley
- Iles, George, 1852-1942
- Iles, Jeff
- Iles, Matthew
- Ilgaz, Cetin
- Ilgen, Lewis Wallace.
- Ilgenfritz Orchids (Nursery),
- Ilgenfritz, Charles A.
- Ilgenfritz, Israel E.
- Ilgenfritz, Margaret M
- Ilger, Jan-Michael
- Ilharco, Fernando Albano, 1935-
- Ilias Saxelmcipʻo Universiteti,
- Ilʹi︠a︡shenko, V. I︠U︡. (Valentin I︠U︡rʹevich)
- Ilić Milošević, Marijana
- Ilić, Bojan
- Ilʹichev, V. D. (Valeriĭ Dmitrievich)
- Iliff, David A
- Iliff, Marshall J.
- Iliffe,Thomas M.
- ILINÁ, Anna
- Ilinkin, Vladimir
- Ilinsky, Yuri
- Iliopoulos, Yorgos
- Iliopoulou-Georgudaki, Joan
- Ilizaliturri Hernández, César Arturo
- Iljinsky, Ivan
- Ilka Nurseries.
- Ilkal, M A
- Ilkiu-Borges, Anna L
- Ilkiu-Borges, Anna Lidza
- Ilkiu-Borges, Anna Liza
- Ilkiu-Borges, Anna Luiza
- Ilkiu-Borges, Anna Luiza
- Ilkiu-Borges, Anua L
- Ilkiu-Borges, Fernanda
- Ilkova, Julia
- Illana, C
- Illarionova, Irene D
- Illenseer, Rafael
- Illert, Christopher R
- Illes, Colin
- Illescas Riquelme, Carlos Patricio
- Illg, Paul L
- Illi, Julia
- Illick, J Theron
- Illick, Joseph S. (Joseph Simon), 1884-1967
- Illidge, Rowland
- Illidge, Thomas
- Illies, Joachim
- Illig, Gottwald
- Illiger, Johann Karl Wilhelm, 1775-1813
- Illingworth, J. F., 1870-1949
- Illingworth, Jeanne M.
- Illinik, Jeffrey J
- Illinois Agricultural Association.
- Illinois Archeological Survey.
- Illinois Audubon Society.
- Illinois Coal Strippers Association.
- Illinois Cooperative Crop Reporting Service.
- Illinois Council on Forestry Development.
- Illinois Crop Protection Technology Conference.
- Illinois Duroc Association,
- Illinois Farmers' Institute.
- Illinois Farmers' Institute. Meeting Monmouth, Ill.) 1922-
- Illinois Grape Growing and Wine Making Association.
- Illinois Institute of Natural Resources.
- Illinois Native Plant Society.
- Illinois Natural Areas Inventory.
- Illinois Natural History Society.
- ILLINOIS NATURAL HISTORY SURVEY HAVANA RIVER RESEARCH LAB.
- ILLINOIS NATURAL HISTORY SURVEY HAVANARIVER RESEARCH LAB.
- Illinois Nature Preserves Commission.
- Illinois Nurseries Inc.
- Illinois Nursery.
- Illinois Ornithological Society.
- Illinois Racing Board.
- Illinois RiverWatch Network.
- Illinois Seed & Nursery Co., Inc.
- Illinois Seed Co.
- Illinois Shorthorn Breeders' Association.
- Illinois State Academy of Science.
- Illinois State Agricultural Society.
- Illinois State Bee-keepers' Association.
- Illinois State Dairymen's Association.
- Illinois State Entomologist.
- Illinois State Geological Survey.
- Illinois State Grange.
- Illinois State Historical Library.
- Illinois State Horticultural Society.
- Illinois State Laboratory of Natural History.
- Illinois State Museum Society.
- Illinois State Museum.
- Illinois State Nurserymen's Association.
- Illinois State Water Survey.
- Illinois War Council. 1941-
- Illinois.
- Illinois. Aquatic Biology Section.
- Illinois. Board of live stock commissioners.
- Illinois. Bureau of Family Nutrition.
- Illinois. Center for Aquatic Ecology.
- Illinois. Department of Conservation.
- Illinois. Department of Forestry.
- Illinois. Department of Natural Resources.
- Illinois. Department of Public Works and Buildings.
- Illinois. Department of Registration and Education,
- Illinois. Department of Registration and Education.
- Illinois. Department of Transportation. Wetland Vegetative and Soils Survey Program.
- Illinois. Dept. of Agriculture.
- Illinois. Dept. of Conservation.
- Illinois. Dept. of Conservation. Bureau of Land and Historic Sites.
- Illinois. Dept. of Energy and Natural Resources.
- Illinois. Dept. of Energy and Natural Resources. Office of Research and Planning.
- Illinois. Dept. of Human Services. Bureau of Family Nutrition.
- Illinois. Dept. of Natural Resources.
- Illinois. Dept. of Natural Resources. Office of Scientific Research and Analysis.
- Illinois. Dept. of Public Health.
- Illinois. Dept. of Registration and Education.
- Illinois. Dept. of Transportation. Wetlands Unit.
- Illinois. Division of Animal Industry.
- Illinois. Division of Energy and Environmental Assessment.
- Illinois. Division of Environmental Health.
- Illinois. Division of Fisheries,
- Illinois. Division of Forest Resources.
- Illinois. Division of Forestry.
- Illinois. Division of Stallion Registration.
- Illinois. Division of State Parks.
- Illinois. Division of Water Pollution Control.
- Illinois. Energy and Environmental Assessment Division.
- Illinois. Environmental Protection Agency.
- Illinois. Environmental Protection Agency. Office of Community Relations.
- Illinois. Environmental Protection Agency. Office of Public Information.
- Illinois. Framework Advisory Committee.
- Illinois. Game and Fish Commission.
- Illinois. General Assembly 1859-
- Illinois. Horticultural Board of Control.
- Illinois. LTRMP Havana Field Station.
- Illinois. Natural History Survey Division
- Illinois. Natural History Survey Division. Aquatic Biology Section.
- Illinois. Natural History Survey Division. Center for Biodiversity.
- Illinois. Natural History Survey Division. Center for Wildlife Ecology.
- Illinois. Natural History Survey Division. LTRMP Havana Field Station.
- Illinois. Natural History Survey Division. River Research Laboratory.
- Illinois. Office of Community Services.
- Illinois. Office of Realty and Environmental Planning.
- Illinois. Office of Resource Conservation.
- Illinois. Rivers and lakes commission.
- Illinois. Secretary of state.
- Illinois. Section of Faunistic Surveys and Insect Identification.
- Illinois. Section of Wildlife Research.
- Illinois. Stallion Registration Board.
- Illinois. State Board of Fish Commissioners.
- Illinois. State Entomologist.
- Illinois. State Fish Commission.
- Illinois. State Geologist
- Illinois. Water Resources and Land Use Priorities Task Force.
- Illman, William I.
- Illmann, Gudrun
- Illmensee, Karl
- Illoldi-Rangel, Patricia
- Illustrated American Expedition to the San Juan Region (1892)
- Ilmonen, Jari
- Ilnomac Gardens.
- Ilot, Charles
- Ilse, Hugo, 1835-1900
- Iltchenco, Janaina
- Iltis, A
- Iltis, Hugh H.
- Iltis, Hugo, 1882-1952
- Ilunga Wa Ilunga, Edouard