| CIS SUD S.r.l. | Rome |
| CISEL S.r.l. | Ancona |
| Cistelaier S.p.A. | Modena |
| Cittando S.r.l. | |
| Citybility S.r.l. | |
| CJB Computer Job S.r.l. | Brescia |
| Claudio Gagliardini | Cremona |
| Cleafy S.p.A. | |
| Clearbox AI | Turin |
| Clessidra Private Equity SGR S.p.A. | |
| CleverBit S.r.l.s. | |
| CLIC di Antonino Argentati | Caltanissetta |
| ClioCom | Lecce |
| Clipperz | Bologna |
| Clona system | Bari |
| Cloudbase Solutions S.r.l. | |
| Club Acceleratori | Milan |
| Club Digitale S.r.l. | Milan |
| Clusit - Associazione Italiana per la Sicurezza Informatica | Milan |
| Cluster Pos S.n.c. | Vicenza |
| CMA robotics SpA | Friuli-Venezia Giulia |
| CMM S.a.s. | Monza and Brianza |
| CMT Circuiti Stampati | Teramo |
| CoDe RTD S.r.l. | |
| Codemotion S.r.l. | |
| Codencode | Isernia |
| Coderblock S.r.l. | Palermo |
| CodyHouse | |
| Cogepa Telecommunication S.p.A. | Naples |
| Cointec S.r.l. | Naples |
| ColorToner.it | Chieti |
| Colossus Digital | Rome |
| Comau | |
| Comed S.r.l. | Naples |
| Comfra Cables & Wires S.r.l. | Vicenza |
| Comma3 | Bari |
| Components Engine S.r.l. | Forlì-Cesena |
| Compushop | Pavia |
| Computer Gross S.p.A. | |
| Computer Halley | Sondrio |
| Computer Line Associates S.r.l. | Piacenza |
| Computer System S.n.c. | Verona |
| Computer Time S.r.l. | L'Aquila |
| Computherm S.r.l. | Turin |
| coMwork S.r.l. | |
| Concept | Milan |
| Concrete S.r.l. | Padua |
| Conferenza Rettori delle UniversitĂ e Istituzioni Pontificie Romane | Rome |
| Connecta S.r.l. | |
| Connectica S.a.s. | Turin |