| Smart S.r.l. | Bologna |
| Smart Touch | Varese |
| SmartCAE S.r.l. | Florence |
| SmartDHOME S.r.l. | Milan |
| SmartFAB S.r.l. | |
| Smartpricing.it | Trento |
| Smartware S.n.c. | Lecco |
| Smau Servizi S.r.l. | Milan |
| SMCP Technology | Bergamo |
| SME UP S.p.A. | Turin |
| Smet.it | Padua |
| SMS Italia S.r.l. | Milan |
| Smshosting | Belluno |
| SN Web Solution | Brescia |
| Snap Communication S.r.l. | |
| Snapback.io | Rome |
| SO.MA.CI.S. S.p.A. | Ancona |
| SO.MUS.AR. di Aliverti-Piuri Francesco & C. s.a.s. | Milan |
| SOASI soc.coop. | Forlì-Cesena |
| Soaviem S.r.l. | Salerno |
| Soccerment S.r.l. | |
| Social Academy S.r.l. | |
| SocialWeb Solutions S.r.l. | |
| SOCO | Milan |
| Socrate Sistemi S.r.l. | Savona |
| Sofos S.r.l. | Bologna |
| Soft Way S.r.l. | Novara |
| Soft'n Rock | Teramo |
| Soft-in S.r.l. | |
| Soft.Lab S.r.l. | Benevento |
| Softa S.r.l. | |
| Softcare Studios S.r.l.s. | Rome |
| SoftCUBE S.r.l. | |
| Softeam S.p.A. | Lecco |
| SofTeam S.r.l. | Monza and Brianza |
| Softec S.p.A. | Milan |
| SofTech S.r.l. | Bologna |
| Softer Bologna S.r.l. | Bologna |
| Softing Consulting S.r.l. | Chieti |
| Softing S.r.l. | Rome |
| SoftJam S.p.A. | Milan |
| Softlab Holding S.r.l. | Rome |
| Softlab S.p.A. | |
| Softobia S.r.l. | Cagliari |
| Software Development Vault S.r.l. | Varese |
| Software e Servizi per l'Ingegneria S.r.l. | Ferrara |
| Software Link S.r.l. | Monza and Brianza |
| Software Medico | L'Aquila |
| Software Paradiso | Rome |
| Software-house | Bergamo |