- Ahumada, Mauricio
- Ahumada, Patricio
- Ahumada-Rudolph, Ramón
- Ahumada-Sempoal, Miguel Ángel
- Ahyong, Shane T.
- Ai, Hong-Mu
- Ai, Takano
- Aibar, Pablo
- Aibek, Ulykpan
- Aich, Helga
- Aichele, F. J., Jr.
- Aichele, Fr
- Aichele, James H.
- Aida, Katsumi
- Aida, T
- Aidar, Davi S.
- Aidar, Elizabeth
- Aidar, Marcos Pereira Marinho
- Aidar, S. T.
- Aide, T. Mitchell
- Aidley, D J
- Aiello, Annette, 1941-
- Aiello, Anthony S.
- Aiello, Dalia
- Aiello, Edward
- Aigner, Andreas
- Aigner-Abafi, L
- AIGNON, Hyppolite Lougbégnon
- Aigo, Juana
- Aigret, [Louis] Clément [Joseph] 1856-1921
- Aijsten, Major E E
- Aikawá, Hideki
- Aikawa, Minwa, active 1806-1821
- Aiken Nurseries.
- Aiken, Charles Edward Howard, 1850-1936
- Aiken, D E
- Aiken, D W
- Aiken, George D.
- Aiken, J.
- Aiken, Jane
- Aiken, Marie
- Aiken, R B
- Aiken, Ron B
- Aiken, S. G.
- Aiken, Susan G
- Aiken, William E.A. (William Edward Augustin), 1807-1888
- Aikin, Arthur, 1773-1854
- Aikin, John, 1747-1822
- Aikman, A. T. (Alexander T.)
- Aikman, Charles Morton.
- Aikman, E. F.
- Aikman, Frank, 1945-
- Aikman, George,
- Ail-Catzim, CE
- Ailen, A A
- Aili, Qin
- Ailín Masini, Ana Carla
- Ailleux, R
- Ailly, Adolf d'.
- Aime, M Catherine
- Aime, M. Catherine
- Aime, Valcour, 1798-1867
- Aimi, Mitsuru.
- Ain (France)
- Ain, D Duratul
- Ainley, David G.
- Ainley, Marianne 1937-2008
- Ainley, Mark
- Ainley, R G
- Ainsley, Gordon.
- Ainsley, P J
- Ainsley, Phil
- Ainsley, Phillip
- Ainslie, C. N. (Charles Nicholas), 1856-1939
- Ainslie, George G. (George Gooding), 1886-1930
- Ainslie, R C
- Ainslie, Whitelaw, Sir 1767-1837
- Ainsworth Brothers & Co.
- Ainsworth Nebraska Nurseries.
- Ainsworth, Antony
- Ainsworth, Cheron
- Ainsworth, David
- Ainsworth, Ralph Mitchell, 1885-
- Ainsworth, Tracy D
- Ainsworth, William Thomas, 1858-
- Ainsworth-Boone Company.
- Ainsworth-Davis, J. R. (James Richard), 1861-1934
- Air Force Cambridge Research Laboratories (U.S.). Geophysics Research Directorate,
- Air Line Farm,
- Aira, Manuel
- Airaghi, C
- Airaghi, Carlo
- Airamé, Satie
- Aird, P. L.
- Airedale terrier club of New England.
- Aires, Carlos Cesar de Cima
- Aires, Caroline Cotrim
- Aires, Stefano Salvo
- Airola, D A
- Airoldi, J. P.
- Airriess, C N
- Airth, R L
- Airy, George Biddell, Sir, 1801-1892
- Aisbett, Brad
- Aisenberg, Anita
- Aissa, Patricia
- Aistleitner, Eyjolf
- Aistleitner, U.
- Aisyah, Munirah
- Aita, Yoshiaki
- Aitchison, C W
- Aitchison, G D
- Aitchison, James Edward Tierney 1835-1898
- Aitchison, Jonathan C.
- Aitchison, P. E.
- Aitchison, Tony John
- Aitken, Bruce G
- Aitken, Carol
- Aitken, D L
- Aitken, E H
- Aitken, Edward Hamilton, 1851-1909
- Aitken, James D
- Aitken, Patrick Henderson
- Aitken, Peter F
- Aitken, R. D.
- Aitken, Robert J.
- Aitken, Thomas H. G.
- Aitken, W W
- Aitken, William, 1825-1892
- Aitken, William, of Castle Douglas, Scotland.
- Aitken, Yvonne, 1911-2004
- Aitkens, Ferdinand.
- Aiton, William Townsend, 1766-1849
- Aiton, William, 1731-1793
- Aiton, William, 1760-1848
- Aiumsumang, Surachest
- Aiyadurai, Ambika
- Aizawa, Mineaki
- Aizawa, Takeshi
- Aizawa, Tomonushi, 1768-1849
- Aizen, Marcelo A.
- Aizpuru Oiarbide, Iñaki
- Ajakaiye, J.J.
- Ajani, Penelope
- Ajani, Yousef
- Ajasson De Grandsagne, 1802-1845
- Ajayakumar, B
- Ajayakumara, K. M.
- Ajayi, S S
- Ajduk, H
- Aji, Cipto
- Ajiki, Kyoko
- Ajit, V. P.
- Ajith Kumar, C. R.
- Ajlan, Abdul-Aziz
- Aju, Javier
- Ak, Kibar
- Akabane, Shoji
- Akademie der Wissenschaften in Göttingen
- Akademie der Wissenschaften in Wien.
- Akademie der Wissenschaften in Wien. Mathematisch-Naturwissenschaftliche Klasse.
- Akademie ved Ceské republiky
- Akademii͡a nauk SSSR.
- Akademii͡a nauk SSSR. Otdelenie fiziko-matematicheskikh nauk.
- Akademii͡a nauk SSSR. Otdelenie geologo-geograficheskikh nauk.
- Akademisch Museum te Groningen.
- Akademische Jubiläumsstifung (Berlin, Germany)
- Akademischer Naturwissenschaftliche Verein.
- Akademiska Boktryckeriet.
- Akademja Umiejętności w Krakowie.
- Akademja Umiejętności w Krakowie. Wydział Matematyczno-Przyrodniczy
- Akaki, C
- Akala, Angel C
- Akam, Michael
- Akama, Alberto
- Akama, Pierre
- Akamine, Ernest K
- Akan, Hasan
- Akanan, Watana
- Akar, Hamdi
- Akarsha, B M
- Akata, Ilgaz
- Akatsu, Ivan P.
- Akatsuki, Kane'nari, 1793 or 1794-1861
- Akbar, Khalid Farooq
- Akbar, Shahid Ali
- Akbari, Mohammad
- Akbarian, Mohammad Reza
- Aké Assi, Laurent, 1931-2014
- Aké-Castillo, José Antolín
- Akef, M S A
- Akehurst Nurseries,
- Akel, Matt
- Akeley Expedition to British East Africa (1909-1911)
- Akeley, Carl Ethan, 1864-1926
- Akeley, Delia J. (Delia Julia), 1875-1970
- Aken, R. van
- Aken'Ova, Thelma
- Akerman, Alfred.
- Akerman, John Yonge, 1806-1873
- Akerman, K
- Akerman, Kim
- Akers, Charles Edmond, 1861-1915
- Akers, Daryl
- Akers, R C
- Akers, W.H.
- Akersten, William A.
- Akesson, Bertil
- Akesson, Norman B. (Norman Berndt), 1914-
- Akesson, S
- Aketarawong, Nidchaya
- Akey, David Harold
- Akhani, Hossein
- Akhmetova, Lilia
- Akhtar, M Saeed
- Akhtar, Nafisa
- Akhtar, Naim
- Akhtar, S. A.
- Akhter, Atiq
- Akhurst, John
- Akimetz, V S
- Akimichi, Tomoya.
- Akimoto, Shin–ichi
- Akin, Gwynn Collins
- Akin, John Rouse
- Akin, R. M.
- Akinlua, Isaiah Opeyemi
- Akinsanmi, Jamiu Taiwo
- Akintola, Shehu L
- Akinyemi, Oluwatosin
- Akiti, Jacques
- Akiyama, Hiroyuki
- Akiyama, T
- Akizuki, Korehide.
- Akkari, Nesrine
- Akkizov, Azamat
- Akkuş, Mustafa
- Akmali, Vahid
- Akmentins, Mauricio Sebastián
- Akoijam, Romila
- Akov, Shoshana
- Akpagana, K
- Akpan, Etie Ben.
- Akpo, L.-E.
- Akpokodje, E G
- Akram, Ayesha
- Akram, M
- Akrami, Mohammad Ali
- Akre, Roger D., 1937-
- Akrel, Fredrik, 1748-1804