G
- Gabriel (1910–1912)
- Gadabout (1913–1915)
- Gaethmobile (1902–1904, Gaeth 1905-1910)
- Gale (1905–1907)
- Gardner (1920–1931)
- Garford (1908, 1911–1913)
- Gary Six (1914)
- Gas-au-lec (1905–1906)
- Gaslight (1960-circa 1961)
- Gasmobile (1899–1902)
- Gaylord (1911–1913)
- Gaylord (1955–1956)
- Gearless (1907–1909)
- Gearless (1919–1922)
- Gearless Steamer (see Super-Steamer)
- Gem (1917–1919)
- General (1902–1904)
- General Electric (1891–1898, 1902–1903)
- General Electric (1898–1900)
- Geneva (1901–1904)
- German-American (1902–1903)
- Geo (1989–1997)
- Geronimo (1917–1920)
- Ghent (1916–1918)
- Gillette (1916)
- G.J.G. (1909–1914)
- Glasspar (1949–1953)
- Gleason (1909–1913)
- Glide (1903–1920)
- Globe Four (1921–1922)
- Glover (1920–1921)
- Golden Eagle (1906)
- Graham Electric (1903)
- Graham Motorette (1902–1903)
- Graham-Paige (1928–1930; Graham 1930-1947)
- Gramm (1902)
- Granite Falls (see Lende)
- Grant (1913–1922)
- Graves & Condon (see Crown (1908–1910))
- Gray (1922–1926)
- Gray Light Car (1920)
- Great Arrow (1904–1909) (see also Pierce-Arrow)
- Great Eagle (1910–1918)
- Great Smith (see Smith)
- Great Southern (1910–1914)
- Great Western (1910–1916)
- Greenleaf (1902)
- Gregory (1920–1922)
- Greyhound (1914–1916)
- Grinnell Electric (1910–1915)
- Griswold (1907)
- Grout (1900–1912)
- Gurley (1899–1901)
- G.V. (1907)
- Gyroscope (1908–1909)
Read more about this topic: List Of Defunct Automobile Manufacturers Of The United States