| Name | Description | Year Started | Year Ended |
| Jaguar | British car marque of Coventry | 1945 | |
| Jeep | American vehicle marque of Toledo and Detroit | 1963 | |
| Jeffery | American vehicle manufacturer of Kenosha, Wisconsin | 1914 | 1917 |
| Jensen | British vehicle manufacturer of West Bromwich, Staffs. Also Jensen-Healey. Breaks in production 1977-82, 1993-8 | 1936 | |
| Jowett | British vehicle manufacturer of Bradford, Yorkshire | 1906 | 1954 |
| Kaelble | German commercial vehicle manufacturer of Backmang | 1926 | |
| Kaiser | American car manufacturer | 1946 | 1955 |
| Kalmar | Swedish vehicle manufacturer of Kalmar | 1965 | 1974 |
| Karrier | British commercial vehicle manufacturer of Huddersfield/ Luton/Dunstable, Bedfordshire | 1908 | |
| Kassbohrer | German coach builder of Ulm. Also see SETRA | 1912 | 1931 |
| Kenworth | American commercial vehicle manufacturer of Seattle, Washington | 1923 | |
| Kia | Korean car manufacturer of Seoul | 1985 | |
| Krupp | German commercial vehicle manufacturer of Kiel/Essen/ Wilhelmshaven | 1905 | |