| SED Systems | Saskatchewan |
| Sedika Technologies, Inc. | Quebec |
| Sedna Technologies | |
| Sednove, Inc. | Quebec |
| SEED AI | Quebec |
| Seed Electronics, Inc. | British Columbia |
| Seedbox | Quebec |
| SeedLeaf | |
| SeeHits.com, Inc. | Ontario |
| Seelogics, Inc. | Ontario |
| Seerx Technologies, Inc. | Manitoba |
| SeeTHAT.ca | Ontario |
| SeeThrough Web | Ontario |
| SeeWind Design | Ontario |
| Segue Systems | Alberta |
| SEH Computer Systems, Inc. | Ontario |
| SEI Team | |
| SEIGMA | |
| Seika Logiciel | Quebec |
| SeisWare International, Inc. | Alberta |
| Seize Marketing Agency | |
| Sekcore, Inc. | Quebec |
| Selaris Web Media, Inc. | |
| SELC Colleges | |
| Selcom Industries, Inc. | British Columbia |
| Select Communications, Inc. | Alberta |
| Select Media Direct Marketing & Communications | Ontario |
| Selectcom | Ontario |
| Selectcom Telecom | Ontario |
| Selectors' Choice | Ontario |
| Selectrum Communications | Quebec |
| Selester Canada Corporation | Ontario |
| Selkirk College | British Columbia |
| Selkirk Web Solutions | |
| Seltec Computers | Alberta |
| SEM made easy | British Columbia |
| SEM, Inc. | Quebec |
| Semain québécoise de l'informatique libre | Quebec |
| Semaphore Solutions, Inc. | British Columbia |
| SemaThera, Inc. | |
| Semeon Analytics | Quebec |
| SemiCent Software | Ontario |
| Semiconductor Talent, Inc. | Ontario |
| Séminaire de Sherbrooke | |
| SEMLEOX, Inc. | |
| SEMO Creative, Inc. | |
| Semonitor | British Columbia |
| Semper Information Technology, Inc. | |
| SEMPO Canada | Ontario |
| Sencia Canada Ltd | Ontario |