Helen Adams Keller

Howard Atwood Kelly

Frances Oldham Kelsey

Edward Calvin Kendall

Elizabeth Kenny

Har Gobind Khorana

Alfred Kinsey

Flemmie Pansy Kittrell

Robert Koch

Theodor Kocher

Willem Johan Kolff

Charles Everett Koop

Arthur Kornberg

Albrecht Kossel

Edwin G. Krebs

Hans Adolf Krebs

Ernst Kretschmer

August Krogh

Georges Köhler

Elisabeth Kübler-Ross

René Théophile Hyacinthe Laennec

Rebecca Craighill Lancefield

Karl Landsteiner

Alphonse Laveran

Joshua Lederberg

Antoni van Leeuwenhoek

LaSalle D. Leffall, Jr.

Rita Levi-Montalcini

Edward B. Lewis

James Lind

Fritz Albert Lipmann

Joseph Lister

Otto Loewi

Myra A. Logan

Crawford Williamson Long

Konrad Lorenz

Richard Lower

Karl Friedrich Wilhelm Ludwig

Salvador Edward Luria

André Lwoff

Feodor Lynen

John James Rickard Macleod

Anne Sullivan Macy

Mary Mallon

Arnold Hamilton Maloney

Marcello Malpighi

Patrick Manson

William Howell Masters

Barbara McClintock

Elmer Verner McCollum