| CLEC Strategies | Florida |
| Cleerly, Inc. | Colorado |
| Cleevio | California |
| Clementine Creative Agency | |
| Clemson University Holcombe Department of Electrical and Computer Engineering | South Carolina |
| Clemson University School of Computing | South Carolina |
| Clemson University School of Mathematical and Statistical Sciences | South Carolina |
| Clene Nanomedicine, Inc. | |
| Cleo | Illinois |
| Cleo & Nacho Design, Inc. | California |
| Cleo Life Sciences | California |
| Cleo Robotics, Inc. | Massachusetts |
| CleoSci | Minnesota |
| Cleric | |
| Clerio Vision, Inc. | |
| Clerk, Inc. | California |
| ClerkBase | Rhode Island |
| Clerky, Inc. | California |
| CLEU Diagnostics, Inc. | |
| Cleveland Avenue, LLC | Illinois |
| Cleveland Computer Guy, LLC | |
| Cleveland Consulting | Ohio |
| Cleveland Diagnostics, Inc. | Ohio |
| Cleveland Digital Publishing Users Group | Ohio |
| Cleveland Health-Tech Corridor | Ohio |
| Cleveland Institute of Art | Ohio |
| Cleveland Marketing | |
| Cleveland Medical Devices, Inc. | Ohio |
| Cleveland Motion Controls, Inc. | Ohio |
| Cleveland PC Repair | Ohio |
| Cleveland SEO Guy | Ohio |
| Cleveland State University Department of Electrical and Computer Engineering | Ohio |
| Cleveland State University Department of Mathematics and Statistics | Ohio |
| Cleveland Time Clock & Service Company | Ohio |
| Cleveland University-Kansas City | Kansas |
| Cleveland Web Design | |
| Clever | California |
| Clever Canary | |
| Clever Coding, LLC | Utah |
| Clever Components | California |
| Clever Concepts, Inc. | California |
| Clever Media | Colorado |
| Clever Solutions | |
| Clever Zebo | |
| CleverDev Software | |
| CleverDot.com | Ohio |
| CleverFiles | Virginia |
| Cleverfish | Pennsylvania |
| Cleverly Engaged Marketing | |
| clevermethod, Inc. | |