| Cac Air | Dorval | Airlines |
| Cans 4 Cash Collection Service | Verdun | Collection Agencies |
| Canspan | Montréal | Advertising Agencies |
| Carat | Montréal | Advertising Agencies |
| Casadel | Montréal | Advertising Agencies |
| Casca | Boisbriand | Advertising Agencies |
| Catalisis Media | Montréal | Advertising Agencies |
| Catalisis Média | Montréal | Advertising Agencies |
| CBCL | Anjou | Collection Agencies |
| CCL Financial Inc | Montréal | Collection Agencies |
Publicité (Desktop) Publicité (Mobile) |
| CDM Montréal Inc | Montréal | Advertising Agencies |
| Centre De Ressources Et Promotions Boucher Inc | Montréal | Advertising Agencies |
| CENTURY 21 KAFENA | Dollard Des Ormeaux | Home Decoration & Maintenance, Real Estate Agencies / Agents |
| Cepac Communication | Saint-Lambert | Advertising Agencies |
| CGC Collection Group of Canada | Montréal | Collection Agencies |
| Chambre De Commerce Panamericaine Inc. Cape | Montréal | Advertising Agencies |
| Charka Advertising Inc | Montréal | Advertising Agencies |
| Charlenegendron | Montréal | Advertising Agencies |
| Cinémotion | Montréal | Advertising Agencies |
| CMC Limousine | Montréal | Airlines |
Publicité (Desktop) Publicité (Mobile) |
| Cobra Collection | Montréal | Collection Agencies |
| Collection Charleen | Montréal | Collection Agencies |
| Collection La Marque | Montréal | Collection Agencies |
| CommDesign | Montréal | Advertising Agencies |
| Communicor | Westmount | Advertising Agencies |
| Comptabilité CG | Longueuil | Advertising Agencies |
| Comunika | Montréal | Advertising Agencies, Tout Entreprises et services |
| Consulmaxx | Montréal | Advertising Agencies |
| Continental Airline | Dorval | Airlines |
| Contxtful | Montréal | Advertising Agencies |
Publicité (Desktop) Publicité (Mobile) |
| Cossette | Montréal | Advertising Agencies |
| Coup D'Pub | Montréal | Advertising Agencies |
| Courtiers En Nolisement | Mont-Royal | Airlines |
| Credit Trans-Canada | Montréal | Collection Agencies |
| Création Synergia | Montréal | Advertising Agencies |
| Crédit Fédéral Commercial | Saint-Léonard | Collection Agencies |
| Crédit Protection | Pierrefonds | Collection Agencies |
| Crédit Protection ED Ltée | Montréal | Collection Agencies |
| Cubana Airlines | Montréal | Airlines |
| Cusmano Communications Inc | Saint-Léonard | Advertising Agencies |
Publicité (Desktop) Publicité (Mobile) |
| Day Agency | Montréal | Advertising Agencies |
| DEROS, Carol | Laval | Home Decoration & Maintenance, Real Estate Agencies / Agents |
| Destination Airlines | Montréal | Airlines |
| Desydesign | Montréal | Advertising Agencies |
| Diapason FG Inc | La Prairie | Advertising Agencies |
| Did Communications Ltee | Saint-Léonard | Advertising Agencies |
| Diogo Communications & Design | Anjou | Advertising Agencies |
| Discovery Air Inc | Dorval | Airlines |
| Dixon Collection Agency | Mont-Royal | Collection Agencies |
| Dr Media | Saint-Léonard | Advertising Agencies |
