- germ plasm theory
- germ pore
- germ ring
- germ theory
- germ tube
- Germán Arciniegas
- Gero Crucifix
- gerontic demography
- gerontocracy
- Gerrard Winstanley
- Gerrit Thomoas Rietved
- Gershgorin
- Gershgorin circle theorem
- Gershgorin theorem
- Gershom Gerhard Scholem
- Gershon Shaked
- Gerstmann-Straussler-Scheinker Syndrome
- Gert Dumbar
- Gertrude Belle Elion
- Gertrude crater
- Gertrude Elizabeth Marbaret Anscombe
- Gertrude Jekyll
- Gertrude Käsebier
- Gertrud Elisabeth Mara
- Gertrude Mary Cox