| A2ZPC | Ontario |
| AA Electronics | Ontario |
| AAA Academy & Consulting Ltd | Saskatchewan |
| Aabstract Communications | Ontario |
| AACO Web & Graphic Design | Ontario |
| AAI Canada, Inc. | Ontario |
| AALEN | Ontario |
| Aalstec | Ontario |
| Aalto Technologies | Ontario |
| Aardcom Communications | Ontario |
| Aardcom Registration & Event Services | Ontario |
| Aarialife Technologies, Inc. | Ontario |
| Aaron Vegh | Ontario |
| AARtech Canada | Ontario |
| Aasman | Yukon |
| AATEL Communications, Inc. | Ontario |
| AaZ Netmédia, Inc. | Quebec |
| ABACOM Technologies, Inc. | Ontario |
| Abacus Agency | |
| Abacus.ca Webhosting Services | Ontario |
| AbacusBridge | Ontario |
| Abalone Construction | British Columbia |
| AbapLab | Quebec |
| AbaQus | |
| Abatech Computer Home Service Niagara Ltd | Ontario |
| Abaxio, Inc. | Quebec |
| AbbaTek Group, Inc. | Newfoundland and Labrador |
| ABBMC Micro Ordinateurs | Quebec |
| AbbVie Corporation | |
| ABC Business Services | British Columbia |
| ABC Communications | British Columbia |
| ABC Computer Sales and Services | British Columbia |
| ABC Data Conseil | Quebec |
| ABC Informatique | Quebec |
| ABC Web Wizard | Ontario |
| AbCellera Biologics, Inc. | British Columbia |
| Abdera Therapeutics | British Columbia |
| Abele Design | Quebec |
| ABELSoft, Inc. | Ontario |
| Abenaki Associates | Ontario |
| Abendago Media Group, Inc. | British Columbia |
| Aberdeen International | |
| Aberrant Software, Inc. | Ontario |
| ABF Software, Inc. | British Columbia |
| ABF-DEV.COM | British Columbia |
| ABI Systems | Ontario |
| Abilis Solutions, Inc. | Quebec |
| Ability Business Computer Services | Ontario |
| Abinsi Solutions Group, Inc. | Alberta |
| Abipa Canada, Inc. | |