| University System of New Hampshire | New Hampshire |
| University Venture Fund | Utah |
| Univfy, Inc. | California |
| Univision Computers | Montana |
| Univox Internet, Inc. | Florida |
| UnivSoftware, Inc. | Nevada |
| Uniwebb Software, LLC | California |
| Unix Guru Universe | California |
| UnixEd | Michigan |
| UnixPackages, Inc. | Washington |
| Unixservice, LLC | Oregon |
| Unknown Worlds Entertainment | California |
| Unleaded Software, Inc. | Colorado |
| Unlearn | California |
| Unleash, Inc. | |
| Unleashed Productions, Inc. | Arizona |
| Unleesh, LLC | |
| Unlimited Conferencing | California |
| Unlimited Media | Ohio |
| Unlimited Studios | Puerto Rico |
| Unlimited Technologies, Inc. | Florida |
| Unlimited Web Designs | Florida |
| Unnanu | Texas |
| Unnatural Products | California |
| Unosquare, Inc. | Oregon |
| Unova Technologies, LLC | Arizona |
| Unovis Asset Management | |
| Unqork | New York |
| Unravel Biosciences, Inc. | Massachusetts |
| Unravel Data | California |
| Unravel Technologies, LLC | Wyoming |
| Unreal Engine | North Carolina |
| UnReal Web Marketing | |
| Unreasonable Capital | Colorado |
| UnRiskIT | Texas |
| Unroll.me, Inc. | New York |
| Unscrambl, Inc. | Georgia |
| Unshackled Ventures | California |
| unSkript, Inc. | |
| Unspun | |
| Unstack, Inc. | Massachusetts |
| Unstoppable Software | Ohio |
| Unstructured | |
| Unstuck Labs | |
| UnsubCentral | Texas |
| Unsupervised, Inc. | Colorado |
| Untangle | California |
| Untangled Technology | Ohio |
| Untappd, Inc. | |
| Untapped Labs, Inc. | California |