| 4it, Inc. | Florida |
| 4M Analytics | Texas |
| 4M Consulting, LLC | Colorado |
| 4M Therapeutics, Inc. | |
| 4me, Inc. | California |
| 4P Therapeutics | |
| 4PCTechs, Inc. | California |
| 4PointDigital | New Jersey |
| 4Pros Solutions, Inc. | New Jersey |
| 4RWEB, Inc. | New Jersey |
| 4SecureMail, LLC | Virginia |
| 4Semi Used Semiconductor Equipment | New Jersey |
| 4Service, Inc. | California |
| 4Site Interactive Studios | District of Columbia |
| 4SiteDigital, LLC | Missouri |
| 4SProducts | Florida |
| 4Team Corporatio | Florida |
| 4Team Corporation | Florida |
| 4th Dimension Computers & Technology | Washington |
| 4URSPACE, LLC | New York |
| 4W Technologies | New Jersey |
| 4WEB Medical | Texas |
| 4What, LLC | Florida |
| 4Wires Communications | New York |
| 4x3, LLC | Pennsylvania |
| 5 Calls Civic Action | California |
| 5 Point Data Systems, Inc. | Ohio |
| 5'Odezyn | Texas |
| 500 Designs, Inc. | |
| 500 Startups | California |
| 500px, Inc. | |
| 50megs.com | Utah |
| 51 Blocks SEO | Colorado |
| 51 Oakwood, Inc | Ohio |
| 518WebDesign.com | New York |
| 52 Ltd | Oregon |
| 521 Dimensions, LLC | Wisconsin |
| 540SEO | Oregon |
| 55 Institutional Partners, LLC | Massachusetts |
| 561Media, Inc. | Florida |
| 5AM Venture Management, LLC | California |
| 5B Technologies, Inc. | Idaho |
| 5by5 Design, LLC | |
| 5D Networks | Nevada |
| 5DT, Inc. | California |
| 5Fold | |
| 5G Americas | Washington |
| 5G Technology World | Ohio |
| 5GStore.com | Illinois |
| 5ivecanons Advertising and Marketing Agency | |