| IDrive | New South Wales |
| Idronic | Queensland |
| IDT Australia | Victoria |
| IDX | New South Wales |
| iExperts | New South Wales |
| If You Build It | New South Wales |
| iFactory Pty Ltd | Queensland |
| iFLYflat Pty Ltd | |
| Ignite Creative | New South Wales |
| Ignite Search | |
| Ignition | New South Wales |
| Ignition | New South Wales |
| Ignition Creative | Queensland |
| Ignition Media | Queensland |
| iiNet Ltd | Western Australia |
| Illuminate Systems | New South Wales |
| Illuminated Software | South Australia |
| iMade Systems | Victoria |
| Image Traders | New South Wales |
| ImageOz.com Pty Ltd | Queensland |
| iMagic Pty Ltd | Western Australia |
| iMagic Software | Western Australia |
| IMAGING | Victoria |
| Imagion Biosystems Ltd | Victoria |
| iManageIT Business Services | Queensland |
| IMASEO Pty Ltd | Queensland |
| IMB Bank | |
| Imexpert | New South Wales |
| Immediation Pty Ltd | Victoria |
| Immuron Ltd | Victoria |
| Immutable | New South Wales |
| Immutep Ltd | New South Wales |
| ImmVirX Pty Ltd | New South Wales |
| Impact Systems | New South Wales |
| Impagination | Victoria |
| ImpexDocs | New South Wales |
| Imugene Ltd | New South Wales |
| In Marketing We Trust | New South Wales |
| in. Studio + Cafe | South Australia |
| InBlue Web Media Pty Ltd | New South Wales |
| INCO Australia | |
| Increaseo | New South Wales |
| Incsub, LLC | Victoria |
| Incubate | New South Wales |
| Incubeta | New South Wales |
| InDebted Holdings Pty Ltd | |
| Independent Computer Retailers (ICR) Pty Ltd | Queensland |
| Independent Studios | Victoria |
| Indigo Web Pty Ltd | Queensland |
| Inducta Pty Ltd | New South Wales |