| Search Engine People, Inc. | Ontario |
| Search Gurus, Inc. | Ontario |
| Search Results Media | |
| Search Revolution | |
| Search+Gather | |
| Search3w, Inc. | Alberta |
| Searchandfind.ca | |
| SearchBeyond | Alberta |
| SearchBoostMarketing.com | Ontario |
| SearchEngineOp | Ontario |
| SearchingWorks, Inc. | Ontario |
| SearchKings | Ontario |
| SearchWarrant | Ontario |
| Searidge Technologies | Ontario |
| Searing Media, Inc. | Saskatchewan |
| Seascape Web Interactive | British Columbia |
| SeaSharp Web Services | Nova Scotia |
| Seaside Communications | Nova Scotia |
| SeasonedPros | |
| SEATAC | |
| Seatech Systems Integration, Inc. | |
| SeatGeek | |
| Seaway Social Media | Ontario |
| SecDev | Ontario |
| Second Flux Information Services | British Columbia |
| Secrest Resources Ltd | British Columbia |
| Secret Location | Ontario |
| Sector Host | Saskatchewan |
| Sectoral Asset Management | |
| Sécur-Icare, Inc. | Quebec |
| Secur-ITech | |
| Secur3D | |
| Secur3D, Inc. | |
| Secure by Design | British Columbia |
| Secure City Solutions | Ontario |
| Secure Links | Ontario |
| Secure SMTP Server | Ontario |
| SecurEcom | Quebec |
| SecureIP Solutions | Quebec |
| SecureKey Technologies, Inc. | Ontario |
| SecureOPS, Inc. | Quebec |
| Securicom | |
| Securicore | Ontario |
| Security Compass and SD Elements, Inc. | Ontario |
| Security Conference | Ontario |
| Security ONE Alarm Systems | Ontario |
| Security Solutions | Ontario |
| Security.ca | |
| SecuritySpace | Ontario |
| Securmax, Inc. | Quebec |