| Arete Venture Capital | |
| Arexcon Technologies | Quebec |
| ARGO Data Resource Corporation | Ontario |
| Argus Telecom International, Inc. | Quebec |
| Aria Solutions, Inc. | Alberta |
| Aries Flexographics Ltd | Ontario |
| Arima Network Solutions, Inc. | British Columbia |
| Arima, Inc. | Quebec |
| Arisoft, Inc. | Ontario |
| ARIV | |
| ARIVsys Software, Inc. | |
| Arizon Technologies, Inc. | Ontario |
| ArjanTech Solutions | Ontario |
| Arkonstructs | |
| Arkwell Agency Ltd | |
| Arkys | Quebec |
| ARL Group of Companies Ltd | Ontario |
| ARM Software Consultancy, Inc. | |
| ARMA Biosciences | |
| Armada Data Corporation | |
| Armagh Cash Register Ltd | Ontario |
| ArmCode | British Columbia |
| Armilla | |
| Armira | |
| Armony.bio | |
| Armour Technology Solutions, Inc. | Ontario |
| ARMS, Inc. | Newfoundland and Labrador |
| Armstrong Partnership | Ontario |
| ARN Québec | |
| Arneeon Media | Saskatchewan |
| Arnica Software Corporation | Ontario |
| Aro Systems, Inc. | |
| Arolytics | Alberta |
| Aroma Web Design | British Columbia |
| Around KW Hosting | Ontario |
| Around The Clock Web Designers, Inc. | Ontario |
| Arrai Innovations, Inc. | Alberta |
| Array Design | Ontario |
| ARRAY Development | Ontario |
| Arrivage | |
| Arrow Geomatics, Inc. | Ontario |
| Arrow Web | |
| Arrowsmith Corporation | Ontario |
| Arrox Creative Marketing Agency | |
| Arsenal Web | Quebec |
| Art & Science | Ontario |
| Art Collision | |
| Art Design | Ontario |
| Art Gate VR | Ontario |
| Art Plus Code, Inc. | |