| Seven Internet Ltd | Hampshire |
| Seven Investment Management, LLP | |
| Seven52 | Greater Manchester |
| Seventy9 | Northamptonshire |
| Severn Biotech Ltd | |
| Severn Communications Ltd | |
| Severn Seed Finance | |
| SF Media Solutions Ltd | Nottinghamshire |
| SFC Capital | |
| sfG Software Ltd | Highland |
| SFI Media Ltd | Devon |
| SFJ Systems | |
| SFL Mobile Radio | Merseyside |
| SG Capital Partners | |
| SGOR | Rhondda Cynon Taf |
| Shackle Group Ltd | |
| Shackleton Advisers Ltd | |
| Shackleton Rollin Creative | West Yorkshire |
| Shaderware Ltd | County Durham |
| Shadow Robot Company | |
| Shadowcat Systems Ltd | Lancashire |
| Shake It Up Creative Ltd | |
| Shakespeare Intelligence Ltd | |
| Shape Works Digital Ltd | |
| Shaped By | |
| Shapeshyft | |
| Shaping Cloud | |
| Shapley Tech Ltd | Devon |
| Sharegain Ltd | |
| ShareIn Ltd | |
| Sharp Applications Ltd | Edinburgh |
| Sharp Brains | |
| Sharp Coders Ltd | |
| Sharp Software Developments | Kent |
| Sharp Tech IT Solution | |
| SharpCloud | |
| Sharpmonkeys | |
| Shasha Network | |
| SHE Software Ltd | South Lanarkshire |
| Shearweb | |
| SheCanCode | |
| Sheffield Business Systems Ltd | South Yorkshire |
| Sheffield Hallam University | South Yorkshire |
| Sheffield Haworth | |
| Sheffield Quantum Centre | |
| Shelton Associates | |
| Shepway Computer Services | Kent |
| Sherbet Donkey Media | |
| Sherborne Sensors | Hampshire |
| Sheridan Computers Ltd | |