| Dolon Sofware Solutions, Inc. | British Columbia |
| Dolphin Enterprises | British Columbia |
| Domain Bits | Ontario |
| Domain Cocoon | Quebec |
| Domain Registry of Canada | Ontario |
| Domain Traffic Media Ltd | British Columbia |
| Domain.ca | Manitoba |
| Domain7 | British Columbia |
| DomainAgents Platform, Inc. | |
| DomainePlus.com | Quebec |
| DomainPeople | British Columbia |
| Domains Under | Alberta |
| DomainsCanada.ca | Alberta |
| DOmedic | Quebec |
| Domicity Ltd | Ontario |
| Domilia | |
| DomiNet | British Columbia |
| Dominic Systems Ltd | British Columbia |
| Dominion Business Machines | Ontario |
| dominKnow, Inc. | Ontario |
| Domotique SECANT, Inc. | Quebec |
| Don Hameluck Usability Consulting, Inc. | Ontario |
| Don Structure Ltd | Alberta |
| Doncor.com | Ontario |
| Done | |
| done by dale Web Design | Ontario |
| Done Right Computer Services | |
| Donna Cona, Inc. | Ontario |
| Données Quéebec | Quebec |
| DonriveIT | |
| Dood, Inc. | |
| Dooly | British Columbia |
| DoorBoss.com | Ontario |
| Dora's Web World | Ontario |
| Doric Lenses, Inc. | Quebec |
| DORO, Inc. | Ontario |
| DOSarrest Internet Security Ltd | British Columbia |
| Dot Eco | British Columbia |
| Dot Health | Ontario |
| DOT Simple, Inc. | Nova Scotia |
| Dot Specialists | Alberta |
| Dot-ca-registry.ca | British Columbia |
| DOT.ca | Ontario |
| Dotcalm Computing | Ontario |
| dotCanada | Ontario |
| Dotcode | |
| Dotcom | Quebec |
| Doteasy | British Columbia |
| Dotfusion | Ontario |
| DotH Solutions | Ontario |