- Karel Jaroslav MaškaBorn: August 28, 1851Occupation: pedagogue
- Karl Barry SharplessCitizenship: United StatesBorn: April 28, 1941
- Karl BockischCitizenship: GermanyBorn: January 10, 1874
- Karl Maria KaufmannCitizenship: GermanyBorn: March 2, 1872
- Karol PollakCitizenship: PolandBorn: November 15, 1859
- Kashiwa ŌyamaCitizenship: JapanBorn: June 2, 1889
- Katsuhiko SatōCitizenship: JapanBorn: August 30, 1945
- Kazuo YamagishiCitizenship: JapanBorn: April 28, 1934
- Ken KeelerCitizenship: United StatesBorn: December 2, 1961
- Kenzo SuzukiCitizenship: JapanBorn: 1950
- Kesao TakamizawaCitizenship: JapanBorn: 1952
- Kim IlhunCitizenship: South KoreaBorn: 1909
- Klaus ConradCitizenship: GermanyBorn: June 19, 1905
- Klim ChuryumovCitizenship: Soviet UnionBorn: February 19, 1937
- Knud SchroederCitizenship: Kingdom of DenmarkBorn: July 20, 1877
- Konstantin NovoselovCitizenship: United KingdomBorn: August 23, 1974
- Krzysztof StanekCitizenship: PolandBorn: 1968
- Kōyō KawanishiCitizenship: JapanBorn: January 18, 1959