Medicine: Biographies
- John Scott Haldane
- John Snow
- Jonas Edward Salk
- Joseph E Murray
- Joseph Erlanger
- Joseph Leidy
- Joseph Lister 1st Baron Lister
- Joycelyn Elders
- Jules Bordet
- Julius Wagner-Jauregg
- Karl Gegenbaur
- Karl Landsteiner
- Konrad Emil Bloch
- Lewis Thomas
- Lorenz Heister
- Luigi Galvani
- Marcello Malpighi
- Margaret Higgins Sanger
- Marie Carmichael Stopes
- Marie Curie