| Archangel Media, Inc. | Ontario |
| Arche Innovation | |
| Arche TI | Quebec |
| Archelon, Inc. | Ontario |
| Archiact | British Columbia |
| Archidata, Inc. | Quebec |
| Architech Solutions | Ontario |
| Architexture | British Columbia |
| Archive Digital | British Columbia |
| Archon Systems, Inc. | Ontario |
| Arcitura Education, Inc. | British Columbia |
| Arcline (2000), Inc. | Ontario |
| ARCO Computers | Ontario |
| Arcos Technologies, Inc. | |
| ARCS Group Ltd | Ontario |
| ArcTern Ventures | Ontario |
| Arctic Data Corporation | British Columbia |
| Arctic Digital Ltd | Northwest Territories |
| Arctic Leaf | |
| Arctic Palm Technology, Inc. | Ontario |
| Arctiq | |
| Arcturus Networks, Inc. | Ontario |
| Arcturus, Inc. | Nova Scotia |
| Arctus | Quebec |
| Arcuve | Alberta |
| ARCX, Inc. | Ontario |
| ARDA Power, Inc. | Ontario |
| Ardco.ca | Ontario |
| Ardea Outcomes | Nova Scotia |
| Ardecom | Quebec |
| Ardent Development | New Brunswick |
| Ardexus, Inc. | Ontario |
| Ardoise Design, Inc. | |
| Ardra | |
| AReNA | |
| Arescon Ltd | British Columbia |
| Aretas Sensor Networks | |
| Arete Software, Inc. | Ontario |
| 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 | |
| Arizon Technologies, Inc. | Ontario |
| ArjanTech Solutions | Ontario |