| Clarice Gomes Designs | Ontario |
| Claridion, Inc. | Quebec |
| Clariprod | |
| Claris Media | British Columbia |
| Clariti | British Columbia |
| Clarity Hosted Solutions | Ontario |
| Clarity Recruitment | |
| Clarity Web Design Studio | Alberta |
| Clarity.ca, Inc. | Alberta |
| ClarityIT | Ontario |
| Clark Influence | |
| Clark Marketing Communications | Ontario |
| Clark Software Systems, Inc. | Ontario |
| Clark-Tech, Inc. | Alberta |
| Clarke-Reavley Consultants | British Columbia |
| Clarus Illico Communications | Quebec |
| ClassAxe Multimedia, Inc. | Ontario |
| Classcraft | Quebec |
| Classe Affaires | Quebec |
| Classic Pos, Inc. | Ontario |
| Classic Software Corporation | Ontario |
| Classmate | British Columbia |
| ClassTop | |
| Clavis Social | Ontario |
| CLD Abitibi | |
| Clé en main Distribution | Quebec |
| Clé en main informatique | Quebec |
| Clean Energy Canada | British Columbia |
| Clean Slate Studios | Ontario |
| Clean Valley CIC | Nova Scotia |
| Clean50 | |
| CleanPix Corporation | Alberta |
| Clear Blue Technologies | |
| Clear Case Computers | Ontario |
| Clear Concepts | Manitoba |
| Clear Destination | Quebec |
| Clear Digital | Ontario |
| Clear Path Sales Marketing Group | |
| Clear Power Solutions, Inc. | New Brunswick |
| Clear Solutions | |
| Clear System Solutions RD, Inc. | British Columbia |
| Clear View Systems Ltd | British Columbia |
| Clearbridge | British Columbia |
| Clearbridge Media | Ontario |
| Clearcable Networks | Ontario |
| Clearcanvas Workstation | Ontario |
| ClearCard ATM Service Network, Inc. | Ontario |
| Clearco | |
| ClearDent | British Columbia |
| ClearEdgeConsulting | British Columbia |