| SchoolAI | |
| SchoolCare | Hampshire |
| SchoolRadio | East Riding of Yorkshire |
| Schroders plc | |
| Sci-Net Business Solutions | |
| Sciad Communications Ltd | |
| Scibertec Ltd | Tyne and Wear |
| SciChart Ltd | |
| Science and Technology Facilities Council | Wiltshire |
| Science Angel Syndicate Ltd | |
| Science Creates | |
| Science to Data Science | |
| Science X | |
| ScienceCreates | |
| Sciencesoft Ltd | |
| Scientific Computing World | Cambridgeshire |
| SciLeads Ltd | |
| Scindo | |
| Scindo | |
| SCIS UK Ltd | Lincolnshire |
| Scitech | |
| SciTools | |
| Scolmore International Ltd | Staffordshire |
| Scommerce Mage Ltd | Surrey |
| Scoot Digital Ltd | |
| Scope Communications UK Ltd | Devon |
| Scorchsoft Ltd | West Midlands |
| Scoro | Greater London |
| Scorpion Research Ltd | Greater London |
| ScotComputers Ltd | North Lanarkshire |
| Scotfax | Edinburgh |
| Scothosts | Edinburgh |
| Scotia Biologics Ltd | |
| Scotia Radio Services Ltd | Glasgow |
| Scotland 5G Centre | |
| Scotland's Rural College | |
| ScotlandIS | West Lothian |
| Scotnet | |
| Scott D Smith | Greater London |
| Scott Helme | |
| Scott Logic Ltd | Tyne and Wear |
| Scott Marketing | Hampshire |
| Scottish Association for Marine Science | |
| Scottish Data Systems | |
| Scottish Development International | |
| Scottish Enterprise | |
| Scottish Equity Partners, LLP | |
| Scottish Financial News | |
| Scottish Games Network | |
| Scottish Mathematical Sciences Training Centre | Edinburgh |