| The Machine Design (Oceanside, CA) |
| *MadeThought (London, UK) |
| Magnetik (New York, NY) |
| Mammoth Advertising (Brooklyn, NY) |
| The Matchbox Studio (Dallas, TX) |
| McCann Worldgroup (worldwide) |
| McKinney (Durham, NC) |
| Meat and Potatoes, Inc. (Burbank, CA) |
| Mende Design (San Francisco, CA) |
| MetaDesign (San Francisco, CA) |
| Method (San Francisco, CA. New York, NY) |
| Methodologie (Seattle, WA) |
| Mexican Chocolate Design ( , TX) |
| Mile 44 (Indianapolis, IN) |
| MINE (San Francisco, CA) |
| *Minimaforms ( ? ) |
| Modern Dog (Seattle, WA) |
| Moment Design, Inc (New York, NY) |
| Morris! Communication (San Diego, CA) |
| Mortensen Design (San Francisco, CA) |
| MRM Worldwide (Worldwide) |
| Mucca Design (New York, NY) |
| Myriad Interactive (Scottsdale, AZ) |