- Gabriella HodosánCitizenship: HungaryBorn: 1999
- Gary GygaxCitizenship: United StatesBorn: July 27, 1938
- George AlcockCitizenship: United KingdomBorn: August 28, 1912
- George BoolosCitizenship: United StatesBorn: September 4, 1940
- George de MestralCitizenship: SwitzerlandBorn: June 19, 1907
- George SmithCitizenship: United Kingdom of Great Britain and IrelandBorn: March 26, 1840
- Georges AttardCitizenship: FranceBorn: January 7, 1957
- Georges LemaîtreCitizenship: BelgiumBorn: July 17, 1894
- Gerald PearsonCitizenship: United StatesBorn: March 31, 1905
- Germain Henri HessCitizenship: Canton of GenevaBorn: August 7, 1802
- Giacomo da LentiniCitizenship: ItalyBorn: 1210
- Giacomo Luigi CiamicianCitizenship: Kingdom of ItalyBorn: August 27, 1857
- Giorgio PietrocolaCitizenship: ItalyBorn: November 9, 1950
- Giovan Battista BellasoBorn: 1505Occupation: cryptographer
- Gordon J. GarraddCitizenship: AustraliaBorn: 1959
- Guy ReissCitizenship: FranceBorn: November 8, 1904