| Name | Region |
|---|---|
| Superlinear | |
| Supplimax | |
| SupplyStack N.V. | |
| SurfPlus | Flemish Brabant |
| Swave Photonics | |
| Sweepatic N.V. | |
| SweepBright N.V. | |
| Swift | |
| Sybilla | East Flanders |
| Syensqo | |
| Sygel | Antwerp |
| Sygma-D S.R.L. | Walloon Brabant |
| Sygmanet.be | Limburg |
| Sym3 | West Flanders |
| SYnAbs S.A. | |
| Synchrone | Liège |
| Synergia Medical S.A. | |
| Syneton B.V. | |
| Synexis S.P.R.L. | Brussels-Capital |
| Syngulon S.A. | |
| Syscol S.P.R.L. | Brussels-Capital |
| Système D B.V.B.A. | East Flanders |
| T-Mining N.V. | |
| T-Productions | East Flanders |
| T-Regs | Flemish Brabant |
| Tactics | |
| TAKEOFFANTWERP | |
| Tangent Works | |
| Tappable | |
| Tapptic | Brussels-Capital |
| Targetspot | |
| Tase Research S.A. | Brussels-Capital |
| Team Made | |
| Team Solutions | |
| team.blue | East Flanders |
| Teamleader | |
| Teamwell | |
| Tech Lane Ghent | East Flanders |
| Tech Tour | |
| Tech Tour (Europe Unlimited) | Brussels-Capital |
| Techi S.R.L. | |
| Techne | Flemish Brabant |
| Technocité | |
| Technofutur TIC | Hainaut |
| TechStartupDay | |
| Techtronix | |
| Techvenia | |
| Techventures | |
| Techwin | Antwerp |
| Tectavia | Antwerp |