H
- Haase (1902–1904)
- Hackett (1916–1919)
- H.A.L. (1916–1918)
- Hall (1903–1904)
- Hall (1914–1915)
- Halladay (1905–1922)
- Hamilton (1917)
- Hamlin-Holmes (1919–1929; Hamlin 1930)
- Hammer-Sommer (1902–1904; Hammer 1905-1906)
- Handley-Knight (1921–1923; Handley 1923)
- Hanger (1916)
- Hanover (1921–1927)
- Hanson (1918–1925)
- Harding (1916–1917)
- Hardy (see Flint Roadster)
- Harper (1907–1908)
- Harrie (1925)
- Harris (1910)
- Harrison (1905–1907)
- Harroun (1917–1922)
- Hartley (1895–1899)
- Hartman (1914–1918)
- Harvard (1915–1921)
- Hasbrouck (1900–1902)
- Hatfield (1907–1908)
- Hatfield (1916–1924)
- Havers (1908–1914)
- Hawk (1914)
- Hawley (1906–1908)
- Hay-Berg (1907–1908)
- Haydock (see Cosmopolitan)
- Haynes-Apperson (1896–1905; Haynes 1904-1925)
- Hayward (1913)
- H.C.S. (1920–1925)
- Healey (circa 1905- circa 1916)
- Heine-Velox (1903–1908, 1921–1923)
- Hendel (1903–1904)
- Henderson (1912–1914)
- Henney (1921–1931)
- Henney (1960–1964)
- Henry (1910–1912)
- Henry J (1951–1954)
- Hercules (1914–1915)
- Hercules Electric (1907)
- Herff-Brooks (1915–1916)
- Herreshoff (1909–1914)
- Hertel (1895–1900)
- Hertz (1924–1927)
- Heseltine (1916–1917)
- Hewitt (1906–1907)
- Hewitt-Lindstrom (1900–1901)
- Heymann (1898–1907)
- Hicks (1899–1900)
- Hidley Steam Car (1901)
- Highlander (1919–1922)
- Hill (1904–1908)
- Hilton (1920–1921)
- Hines (1908–1910)
- Hitchcock (1909)
- Hobbie Accessible (1908–1909)
- Hoffman (1901–1904)
- Hoffman (1931)
- Holden (1915)
- Holland (1902–1903)
- Holley (1900–1904)
- Hollier (1915–1921)
- Holly Six (1913–1915)
- Holmes (1906–1907)
- Holmes (1918–1923)
- Holsman (1901–1911)
- Hol-Tan (1908)
- Holtom (1919, 1934)
- Holyoke (1899–1903)
- Homer Laughlin (1916)
- Hood Steamer (1899–1901)
- Hoosier Scout (1914)
- Hoover (1913–1914)
- Hoskins (1920)
- Houpt (1909; Houpt-Rockwell 1910)
- House Steamer (1867)
- Howard (1895–1903)
- Howard (1895, 1901–1904, 1908)
- Howard (1911, 1916–1917, 1919)
- Howard (1913–1914)
- Howey (1907–1908)
- Hudson (1901–1902)
- Hudson (1909–1957)
- Huffman (1919–1925)
- Hummer (1992–2010)
- Hupmobile (1909–1940)
- Hupp-Yeats (1911–1919)
- Huselton (1911–1914)
- Hydromotor (1914–1917)
Read more about this topic: List Of Defunct Automobile Manufacturers Of The United States