| Adam's Cleaning Service | Cleaning Services, Cleaning Service | — |
| Adams Viennese Bakery | Baked Goods Wholesalers | adamsviennesebakery1.placeweb.site |
| Adapters & Batteries Center | Answering Machines & Equipment | facebook.com |
| Adaptiv Networks, Inc. | Tout Informatique et internet | adaptiv-networks.com |
| ADAS Inc. | Aerial Photographers | adasint.com |
| Addition Elle | Boutiques | additionelle.com |
| ADDUM | Community Service & Charitable Organizations | addum.org |
| Adel Hanna | Cleaning Services, Cleaning Service | facebook.com |
| Adel Hanna | Cleaning Services, Cleaning Service | — |
| Adele Inc | Cleaning Services, Cleaning Service | — |
| Adele Zanni | Tout Arts et divertissement | adelezanni.com |
| Adelfilmmaker | Camera & Photo Equipment Stores | adelfilmmaker.wordpress.com |
| Adeline-Thi Mugnier Ostéopathe D.O. | Alternative Health | — |
| Adelson Et Associés | Business Insurance | adelsonassociates.com |
| Adexmat | Cold & Heat Insulation Contractors | adex.ca |
| Adfast Corporation | Tout Entreprises et services | adfastcorp.com |
| AdGear Technologies Inc. | Information Technologies (IT) | — |
| Adglobe | Information Technologies (IT) | adglobe.ca |
| ADH Ébéniste | Furniture Stores | — |
| ADHAP-SOINS | Beauty & Fitness, Hairdressers & Beauty Salons | — |
| Adhésifs Adchem Inc | Caulking Materials & Equipment | facebook.com |
| ADI | Information Technologies (IT) | adiglobal.ca |
| ADI Electrique - Électricien Commercial et Industriel Saint-Laurent | Electricians | adielectric.ca |
| ADI Électrique - Électricien Commercial Montréal | Electricians | adielectric.ca |
| ADISQ | Tout Arts et divertissement, Tout Événements spéciaux | adisq.com |
| Adl | Commercial Kitchen Equipment | — |
| Adler H | Flooring | — |
| ADM Agri-Industries | Agri-food | adm.com |
| ADM Agri-Industries Company | Agri-food | adm.com |
| Admicom | Bookkeeping Software & Accounting Systems | facebook.com |
| ADN Laboratoire Graphique | Advertising Agencies | facebook.com |
| Adonis | Automobiles, Bakery Equipment, Bakery Supplies, Grocery Stores | groupeadonis.ca |
| Adonis Construction Et Démolition | Building Contractors | — |
| Adoption Formons Une Famille (Société Dô) | Adoption Agencies & Services | — |
| ADP Canada R-L | Information Technologies (IT) | adp.ca |
| Adrenalys | Startup Ecosystem | adrenalys.ca |
| Adrien Yves Lighting Design | Boutiques | facebook.com |
| ADS Électrique Inc | Electricians | facebook.com |
| ADT Canada | Information Technologies (IT) | adt.ca |
| ADT Plomberie | Plumbing | — |
| Adtran Canada | Information Technologies (IT) | adtran.com |
| Advanced Business Analytics Inc. | Physiotherapy | — |
| Advanced Collection Services | Collection Agencies | — |
| Advanceit Financial Corp | Computer Networking | advanceit.com |
| Advanomics Corporation | Life Sciences and Health Technologies (LSHT) | agilemv.com |
| Advend | Advertising Agencies | advend.ca |
| Adviso Conseil | Tout Informatique et internet | adviso.ca |
| Adzura | Advertising Agencies | facebook.com |
| Adèle House Cleaning | Cleaning Services, Cleaning Service | adeleondemand.com |
| Adèle Sur Demande - Montréal | Cleaning Services, Cleaning Service | — |
