John Dinsmore and Associates
- Used and rare books; including first editions.
- http://members.autobahn.mb.ca/~parker/jda/

John Drury Rare Books
- Specializing in books dating from 1600 to 1900 with an emphasis in the humanities. Includes economics, education, law, philosophy and social history.
- http://www.johndruryrarebooks.com

Julian's Books
- Specializing in rare and hard to find out of print books; first editions, signed/autographed books, limited editions, leatherbound books and sets.
- http://www.juliansbooks.com/

James and Devon Gray Booksellers
- Antiquarian bookdealer specializing in books printed before 1700.
- http://www.graybooksellers.com/

John Townsend
- Second-hand books for sale on family history, British topography, antiquarian heraldry books, plus free specialist out-of-print book search.
- http://www.johntownsend.demon.co.uk/

James H. Freiberg, Books
- Large selection of out of print, used, rare and antiquarian books in stock covering many fields and interests. Fiction, Non Fiction, History, Childrens, and Cooking.
- http://www.freibergbooks.com/

James S. Jaffe Rare Books
- Specializing in rare books, literary first editions, private press books, illustrated books and poetry.
- http://www.literaryfirsts.com/

Joslin Hall Rare Books
- Curious, Unusual and Interesting Books of the 16th-20th Centuries.
- http://www.joslinhall.com/

Jonathan Sheppard Books
- Genealogical and antiquarian resource for out-of-print books and map reprints.
- http://www.jonathansheppardbooks.com/

John Gach Books
- Used books in Neuroscience, Philosophy, Psychiatry, Psychoanalysis, Psychology and Social Thought.
- http://www.gach.com/

Joseph J. Felcone
- Rare books and New Jerseyana.
- http://www.felcone.com/

JB Books
- Offers searchable database of new, used, and collectible antiquarian books.
- http://www.jbbooks.com/

Janey's Used Romance Book Sale
- Historical, contemporarys, series, and paranormal romances. Prices are in U.K pounds and U.S. dollars
- http://dspace.dial.pipex.com/town/park/ed54/

Jarndyce Nineteenth Century Booksellers
- 18th and 19th Century English Literature, Social, Economic and Political History, Dickens first editions and Dickensiana. Based in London UK.
- http://www.jarndyce.co.uk/

Jeffrey Thomas
- Americana, literature, fine printing, travel, illustrated books, and good books on all subjects.
- http://www.jeffreythomas.com/