Sir Patrick Playfair Laidlaw (born 1881)
Dr. John Ring La Montagne (born 1943)
Eric Steven Lander (born 1957)
Dr. Henry Clifford Lane Jr. (born 1950)
Dr. Robert Salvatore Lanciotti (born 1960)
Robert Samuel Langer Jr. (born 1948)
Dr. Alexander Duncan Langmuir (born 1910)
Lyndon Hermyle LaRouche Jr. (born 1922)
Alexandra "Sasha" Latypova (born 1971)
Dr. James Vincent Lawler (born 1969)
Ciaran Patrick Lawlor (born 1984)
Dr. Marcelle C. Layton (born 1958)
Dr. Esther Miriam (Zimmer) Lederberg (born 1922)
Dr. Joshua Lederberg (born 1925)
Herbert Henry Lehman (born 1878)
Frank Thomson Leighton (born 1956)
Richard Alan Lerner (born 1938)
Rachel Elizabeth Levinson (born 1952)
Dr. Paul Adin Lewis (born 1879)
Irving Lewis "Scooter" Libby (born 1950)
Dr. Charles M. Lieber (born 1959)
Dr. Walter Ian Lipkin (born 1952)
Dr. Margaret Ann Liu (born 1956)
Ira Mann Longini, Jr. (born 1948)
Dr. Daniel Richard Lucey (born 1955)
Dr. Paul Andrew Luciw (born 1948)