| Software Development Lohninger | Lower Austria |
| Software Pointers | Lower Austria |
| Software Quality Experts GmbH | |
| Software-Management GmbH | Upper Austria |
| Softwarehaus Kerth | Vienna |
| Softwarepark Hagenberg | Upper Austria |
| SOFTwerk Professional Automation GmbH | Upper Austria |
| Solution IT Service & Handel e.U. | Vienna |
| Solvistas GmbH | Upper Austria |
| Soma Reality GmbH | |
| Sonible GmbH | |
| Space Generation Advisory Council | Vienna |
| Space Individuals | |
| space24 Websolutions | Lower Austria |
| Spacelend | |
| Sparkasse Oberösterreich Bank AG | Vienna |
| SparxSystems Software GmbH | Vienna |
| Specialis IT GmbH | Styria |
| Speech Code Produktsicherheits GmbH | Vienna |
| Speedinvest | Vienna |
| Speedinvest Heroes Consulting GmbH | |
| Speedinvest Pirates GmbH | |
| Splitbee | |
| SPP digital GmbH | |
| SPP Handelsges.m.b.H. | Vienna |
| Sprecher Automation GmbH | |
| SPS Industrie-Elektrik GmbH | Upper Austria |
| SPS Technik GmbH | Lower Austria |
| Spusu Austria | |
| Spydeception | Vienna |
| Stacked Marketer | |
| Startup Live | Vienna |
| Startup Playground | |
| Startup.Tirol | Tyrol |
| startup300 | |
| StartUs | Vienna |
| StartUs Insights | Vienna |
| StartUs Magazine | Vienna |
| Staymate OG | |
| Steinbauer IT GmbH | Styria |
| STI Innsbruck | Tyrol |
| Stillalive Studios GmbH | |
| Stockwerk Coworking Space Wien | |
| Stormhedge Solutions GmbH | |
| Storyblok GmbH | |
| Storyclash GmbH | |
| StreamUnlimited Engineering GmbH | Vienna |
| Studio for Information Design GmbH | |
| Sulu GmbH | |
| SUNFOX Games GmbH | Vienna |