- Gallo, Robert C. (1937- )
- Gas Vacuoles and Gas Vesicles
- Gastroenteritis
- Gene
- Genetic Code
- Genetic Identification of Microorganisms
- Genetic Mapping
- Genetic Regulation of Eukaryotic Cells
- Genetic Regulation of Prokaryotic Cells
- Genotype and Phenotype
- Germ Theory of Disease
- Giardia and Giardiasis
- Gliding Bacteria
- Globulins
- Glycocalyx
- Golgi Body
- Golgi, Camillo (1843-1926)
- Gonorrhea
- Goodpasture, Ernest William (1886-1960)
- Gotschlich, Emil Claus (1935- )
- Gram Staining
- Gram, Hans Christian Joachim (1853-1938)
- Growth and Growth Media
