- J2TV – from television and film production company formed by Malcolm in the Middle actor Justin Berfield and producer Jason Felts.
- JAL – from Japan Airlines
- Jat Airways – founded in 1927 as "Aeroput" (Airway in Serbian). From 1947, it was known as JAT (Jugoslovenski Aero Transport). After the break-up of the former Yugoslavia (and after Federal Republic of Yugoslavia changed its name to Serbia and Montenegro), the company kept the name, Jat, but not as an abbreviation.
- Jawa Motors – from Janeček (the owner) and Wanderer (the motorcycle product).
- JBL – from James B Lansing, an electronics designer
- J. C. Penney – from James Cash Penney, founder of the department store chain.
- Johnson & Johnson – Originally a partnership between brothers James Wood Johnson and Edward Mead Johnson in 1885, the addition of brother Robert Wood Johnson I led to formal incorporation as Johnson & Johnson in 1887.
- Jordache - from the first names of the Nakash brothers who founded the company: Joe, Ralph, David (Ralph's first son), Avi, plus che, after the second syllable of "Nakash."
- JVC – Japan Victor Company (Victor Company of Japan, Ltd) was founded in 1927 as a US subsidiary, The Victor Talking Machine Company of Japan, Limited. JVC developed the VHS video cassette format.
Read more about this topic: List Of Company Name Etymologies