- Lajos SzilassiCitizenship: HungaryBorn: December 10, 1942
- Landon Curt NollCitizenship: United StatesBorn: October 28, 1960
- Lars OnsagerCitizenship: NorwayBorn: November 27, 1903
- Lars Peter HansenCitizenship: United StatesBorn: October 26, 1952
- Laurens HammondCitizenship: United StatesBorn: January 11, 1895
- Leire MalkorraCitizenship: SpainBorn: 1988
- Leonard KornošCitizenship: SlovakiaBorn: 1956
- Leonid KantorovichCitizenship: Soviet UnionBorn: January 19, 1912
- Leslie PeltierCitizenship: United StatesBorn: January 2, 1900
- Lev LandauCitizenship: Soviet UnionBorn: January 22, 1908
- Louis BardonBorn: September 3, 1874Occupation: Latin Catholic priest
- Louis Charles Émile LortetCitizenship: FranceBorn: August 22, 1836
- Louis DaguerreCitizenship: FranceBorn: November 18, 1787
- Lucjan OrkiszCitizenship: PolandBorn: 1900
- Ludvig FaddeevCitizenship: Soviet UnionBorn: March 23, 1934
- Luigi VassalliCitizenship: Kingdom of ItalyBorn: January 8, 1812
- Léo HouziauxCitizenship: BelgiumBorn: March 23, 1932