| Health & BioTech Accelerator | Milan |
| Healthy Aging Research Group Società Benefit S.r.l. | |
| Hecle S.r.l. | |
| Hej! | Milan |
| Helios S.r.l. | Friuli-Venezia Giulia |
| HEN S.r.l. | Modena |
| Henry Muccini | L'Aquila |
| Hequet Therapeutics | |
| Hercle S.r.l. | |
| Hevolus S.r.l. | |
| Hexagora | Verona |
| Hi-Interiors | Milan |
| Hi-net S.r.l. | Rimini |
| Hicare Research S.r.l. | Turin |
| Hidoly S.r.l. | |
| High Connexion Italia S.r.l. | Como |
| HiNelson S.r.l. | |
| HiRide Suspension S.r.l. | |
| Hiro Robotics S.r.l. | |
| Hisolution S.r.l. | Pisa |
| Hive S.r.l. | |
| Hlpy | |
| Hochfeiler | Rome |
| Hodlie S.r.l. | |
| Hoka Italia | Mantua |
| Holidoit S.r.l. | |
| Holostem Tarapie Avanzate S.r.l. | |
| Hoopygang | |
| Hoplo S.r.l. | Milan |
| Horae S.r.l. | Perugia |
| Hospitex International S.r.l. | |
| HOST S.p.A. | |
| Host.it | Turin |
| HostDeck | Perugia |
| Hostinato S.r.l. | Varese |
| Hosting Center | Rome |
| Hosting Solutions | Florence |
| HostingTEK | Vicenza |
| hotswap | |
| HPA S.r.l. | |
| HRNET S.r.l. | Lodi |
| HSBC Continental Europe, Italy | |
| HSD S.p.A. | |
| HT Italia S.r.l. | Ravenna |
| HTML.it | Rome |
| Hub Innovazione Trentino | Trento |
| HUB Parking Global | Bologna |
| Hubique | |
| Huge! S.r.l. | Bergamo |
| HuKnow | Milan |