| H&MV Engineering | |
| H2 Learning | |
| Halo Business Angel Network | Dublin City Council |
| Hanley Automation | |
| HardSoft Ltd | |
| Hartnett Centre | |
| Hatch Blue | |
| HatchHouse Digital | Dublin City Council |
| HCS | Dublin City Council |
| Health Research Board | |
| Health Tech Ireland Annual Conference | |
| HealthBeacon | |
| HEAnet Ltd | Dublin City Council |
| HEAVEN11 IPDB INC. Ltd | |
| Heaventree | |
| Heidi Computers Ltd | Wicklow County Council |
| Helgen Technologies | |
| Helixworks Technologies Ltd | |
| Hello Humans | |
| HelloWorld Web Technologies Ltd | |
| Helping Networks | |
| Hemdahl | |
| Herbst Software | Wicklow County Council |
| Heritage Ventures Ltd | |
| Hewston Computer Solutions | |
| Hexa Digital Solutions | |
| HeyStaks Technologies Ltd | |
| Hibernia College | |
| Hickey Communications Ltd | Cork County Council |
| Hidden Depth | Dublin City Council |
| High Spec Tech | Dún Laoghaire-Rathdown County Council |
| HiTech Health | |
| Holafly | |
| Hooke Bio Ltd | |
| Horseware Ireland | |
| Host & Co. | |
| Host Ireland | Dublin City Council |
| Host.ie | Fingal County Council |
| Hostelworld Services Ltd | Dún Laoghaire-Rathdown County Council |
| Hosting & Web Solutions | Kildare County Council |
| Hosting Ireland | Waterford City and County Council |
| Hostr | Dublin City Council |
| House of Design | Dublin City Council |
| HR Duo | |
| HSBC Ireland | |
| HSolutions | Limerick City and County Council |
| HST Solutions | Dublin City Council |
| HT Materials Science Ltd | |
| Hublio | |
| Hutchison 3G Ireland Ltd | Dublin City Council |