M
| Publisher | Website | ISBN prefix |
| Magic Carpet Books Inc. | www.magic-carpet-books.com | 0-9774311, 0-9771876, 0-9755331, 0-9766510 |
| Manic D Press | www.manicdpress.com | 0-916397, 1-933149 |
| Marion Boyars Publishers, Ltd. | www.marionboyars.co.uk | 0-7145 |
| Matthew Price Ltd. | www.mathewprice.com | 1-935021 |
| McSweeney's | www.mcsweeneys.net | 1-932416, 0-9703355, 0-9719047 |
| Mercury House
Atlas Press |
www.mercuryhouse.org | 0-916515, 1-56279
1-56279 |
| Milkweed Editions | www.milkweed.org | 0-915943, 1-57131 |
| Milo Books | www.milobooks.co.uk | 1-903854 |
| Monkfish Book Publishing
Provenance Editions |
www.monkfishpublishing.com | 0-9726357, 0-9749359, 0-9766843, 0-9798828
0-9726357 |
| Moonlight Publishing | www.moonlightpublishing.co.uk | 1-85103 |
| Morning Light Press | www.morninglightpress.com | 0-609, 0-930407, 0-9740916, 1-59675 |
| Morpheus International | 0-9623447, 1-883398 | |
| Mount Vernon Press | 0-931213 |
N
| Publisher | Website | ISBN prefix |
| National Lampoon Press | 0-9778718, 0-9788323, 0-9800592 | |
| New Horizon Press | www.newhorizonpressbooks.com | 0-88282 |
| New Internationalist | www.newint.org | 0-9540499, 1-869847, 1-904456, 1-906523, 9974-574 |
| New Rivers Press | www.newriverspress.com | 0-89823334 |
| New Village Press | www.newvillagepress.net | 0-9766054, 0-9815593 |
| New World Library | www.nwlib.com | 0-931432, 1-57731, 1-880032, 1-882591, 1-932073 |
| Newmarket Press | www.newmarketpress.com | 1-55074, 0-93785 |
| NewSage Press | www.newsagepress.com | 0-939165 |
| Nicolo Whimsey | www.nicolowhimsey.com | 1-935550 |
| Nilgiri Press | www.nilgiri.org | 0-915132, 1-58638, 1-888314 |