| Acreative | British Columbia |
| Acro Media, Inc. | British Columbia |
| Acronym Software | Ontario |
| Acropole Media | |
| Acrotechnique International, Inc. | Ontario |
| ACS | Ontario |
| ACS - Applied Computer Systems | Ontario |
| ACS Computer Solutions | British Columbia |
| Acsenda School of Management | |
| Act Analytics | |
| ACT Labs Ltd | British Columbia |
| Act Zero | Ontario |
| ACT360 | Ontario |
| ACTA Press | Alberta |
| ACTAtek | British Columbia |
| actDEN | British Columbia |
| Actel Communication | Quebec |
| Actemium | |
| Actenum | British Columbia |
| Actimind, Inc. | Ontario |
| Action Computer Service | Ontario |
| Action Page, Inc. | Quebec |
| Action Software International | Ontario |
| ActionCOACH | |
| ActionWebServices | Nova Scotia |
| actiTIME, Inc. | |
| Activ8 Corporate Relations, Inc. | British Columbia |
| ACTivate HR | |
| Active Business Growth, Inc. | |
| Active Computer Services | British Columbia |
| Active Disk Editor | Ontario |
| Active RMP | Alberta |
| Active UNDELETE | Ontario |
| Active UNERASER | Ontario |
| ActiveCo Technology Management | British Columbia |
| ActiveConversion | Alberta |
| ActiveData | Quebec |
| ActiveDEMAND | Alberta |
| ActiveIQ | |
| ActiveLabs | Ontario |
| Activeminds Software Ltd | Alberta |
| ActiveState | British Columbia |
| Activis | Quebec |
| Activo, Inc. | Ontario |
| Activus Corporation | Ontario |
| ACTO Technologies, Inc. | Ontario |
| ACTs Computer Training & Services | |
| ACTSolutions.ca | |
| Actua | |
| Actual Tools | British Columbia |