- Carl AkeleyCitizenship: United StatesBorn: May 19, 1864
- Carl ConcelmanCitizenship: United StatesBorn: December 23, 1912
- Carl Friedrich HäberleinBorn: October 28, 1787Died: February 20, 1871
- Carl Josef BayerCitizenship: Austria–HungaryBorn: March 4, 1847
- Carl NägeliCitizenship: SwitzerlandBorn: March 26, 1817
- Carl SchmidtCitizenship: German ReichBorn: August 26, 1868
- Carl W. HergenrotherCitizenship: United StatesBorn: 1973
- Carlo CozioCitizenship: Kingdom of SardiniaBorn: 1715
- Carlo RovelliCitizenship: ItalyBorn: May 3, 1956
- Carlos Ulrrico CescoCitizenship: ArgentinaBorn: November 24, 1910
- Carol Lynn NeeseCitizenship: United StatesBorn: 1958
- Cassius Monroe WebsterCitizenship: United StatesBorn: November 1851
- Charles Brady KingCitizenship: United StatesBorn: February 2, 1868
- Charles ChamberlandCitizenship: FranceBorn: March 12, 1851
- Charles Clement Jennings TaylorCitizenship: United KingdomBorn: 1861
- Charles DarwinCitizenship: United Kingdom of Great Britain and IrelandBorn: February 12, 1809
- Charles Hazelius SternbergCitizenship: United StatesBorn: June 15, 1850
- Charles Marie Benjamin RougetCitizenship: FranceBorn: August 19, 1824
- Charles Spackmann BarkerCitizenship: United Kingdom of Great Britain and IrelandBorn: January 7, 1807
- Charles WilkesCitizenship: United StatesBorn: April 3, 1798
- Charlie BoothCitizenship: AustraliaBorn: October 1903
- Chi, Chün-taoCitizenship: ChinaBorn: 263
- Choe Seok-jeongCitizenship: JoseonBorn: July 2, 1646
- Christel BiensteinCitizenship: GermanyBorn: December 26, 1951
- Christen Leif VebækCitizenship: Kingdom of DenmarkBorn: July 2, 1913
- Christo DaskalovBorn: 1827Occupation: physician
- Christophe DemeautisCitizenship: FranceBorn: 1950
- Christopher AikmanCitizenship: CanadaBorn: November 11, 1943
- Clifford A. PickoverCitizenship: United StatesBorn: September 15, 1957
- Clifford Hugh DowkerCitizenship: CanadaBorn: March 2, 1912
- Conrad M. StibbeCitizenship: Kingdom of the NetherlandsBorn: September 7, 1925
- Constance SpryCitizenship: United KingdomBorn: December 5, 1886
- Cory DoctorowCitizenship: United KingdomBorn: July 17, 1971
- Cumrun VafaCitizenship: United StatesBorn: August 1960