| Symmetrical S.r.l.s. | Rome |
| Sync Lab S.r.l. | Naples |
| Syncdata | Turin |
| Synchron S.r.l. | Rome |
| Syncronika | Milan |
| Synergo Capital SGR S.p.A. | |
| Synesthesia S.r.l. | |
| Syneto | Brescia |
| Synthetic S.r.l. | Messina |
| Syo Solutions S.r.l. | La Spezia |
| Syrto | |
| SYS-DAT Group | Milan |
| Sys-Tek S.r.l. | Turin |
| Sysaround S.r.l. | Milan |
| SysDesign S.r.l. | Trento |
| Sysman Progetti & Servizi S.r.l. | |
| Syspack Computer Italia | Rome |
| System Cable S.r.l. | Reggio Emilia |
| System S.r.l. | Livorno |
| System SpA | Modena |
| System-i | Brescia |
| Systematika Distribution S.r.l. | |
| SySTEP S.n.c. | Naples |
| T-LAB | Frosinone |
| T-Lab S.r.l. | Novara |
| T.NET S.p.A. | |
| T4i - Technology for Propulsion and Innovation S.p.A. | |
| T4Tech S.r.l. | Genoa |
| Taal S.r.l. | |
| Tabasoft | Rome |
| TAC S.r.l. | |
| TaDa S.r.l. | |
| Tagliabue Sistemi S.r.l. | Milan |
| Taglio C S.r.l. | Cuneo |
| Taitus Software Italia S.r.l. | |
| Takai S.r.l. | |
| Takeoff Accelerator | Turin |
| Takis S.r.l. | |
| Talent Garden S.p.A. | |
| Talent Garden S.p.A. | |
| Talents Venture | Milan |
| Talentware S.r.l. | |
| talet-e S.r.l. | |
| Talete S.r.l. | Milan |
| Tam Tam Italia | |
| Tanaza S.p.A. | |
| Target Solutions | Lucca |
| TaTaTu | Rome |
| Tatoosa Creative | Savona |
| Tau Group | Turin |