| Marist College School of Computer Science and Mathematics | New York |
| Maritime Partners, LLC | |
| Marius Pharmaceuticals | |
| Marizyme, Inc. | Florida |
| Marja Corporation | Maine |
| Mark 4 Marketing | |
| Mark Arenz | Indiana |
| Mark Brinker & Associates | Michigan |
| Mark Curlanis Consulting | California |
| Mark Deitch & Associates, Inc. | California |
| Mark Farrah Associates | Maine |
| Mark Howard Webster | Washington |
| Mark III Systems | Texas |
| Mark IV Capital | California |
| Mark J. Nigrini, Ph.D. | West Virginia |
| Mark Labs, Inc. | District of Columbia |
| Mark McLaughlin Design | California |
| Mark Nelson | Texas |
| Mark Simonson Studio | Minnesota |
| Mark Warrick | California |
| Mark Wieman | Washington |
| Mark/Space, Inc. | California |
| Mark43 | |
| Mark43, Inc. | New York |
| Markaaz | |
| Markaaz, Inc. | Texas |
| Markable, Inc. | Washington |
| Markate Corporation | Arizona |
| Marked 2 | |
| Marker Leaning | |
| Marker Therapeutics, Inc. | |
| Marker, LLC | New York |
| Markerly, Inc. | California |
| MarkerSeven | California |
| Markertek | New York |
| Market 8 Group, LLC | Florida |
| Market Communications | New York |
| Market Directions | Massachusetts |
| Market Edge Communications, Inc. | Georgia |
| Market Focus, Inc. | California |
| Market Genius | |
| Market Hero Software, LLC | |
| Market Insight Corporation | |
| Market Intelligence Center | Virginia |
| Market Leader | Washington |
| Market Master | Florida |
| Market Media Connec, Inc. | |
| Market Media Grind, LLC | |
| Market Motive, Inc. | North Carolina |
| Market My Market | |