Abdul Qadeer Khan
Ada Lovelace
Adalbert Czerny
Adolphe Quetelet
Agnes Arber
Alan Turing
Alberto Santos-Dumont
Albrecht von Haller
Aldo Leopold
Alessandro Volta
Alexander Bain
Alexander Graham Bell
Alexander von Humboldt
Alexandra Navrotsky
Alfred Binet
Alfred Blalock
Alfred Kinsey
Alfred Nobel
Alfred Russel Wallace
Alfred Wegener
Alister Hardy
Ambrose Fleming
Amedeo Avogadro
Anaximander
Anders Celsius
Andreas Vesalius
Anna Missuna
Antoine Lavoisier
Antonie van Leeuwenhoek
Antonio Meucci
Archimedes
Aristotle
Arnold Orville Beckman
Arnold Sommerfeld
Arthur Eddington
Artturi Virtanen
Avicenna