| City of Hope | |
| City of Oaks Marketing | |
| City Ranked | |
| City Startup Labs, Inc. | North Carolina |
| City Therapeutics | |
| City University Los Angeles | California |
| City University of New York | New York |
| City University of Seattle | Washington |
| CityBldr | Washington |
| CityCenter Co. | California |
| CityCheers Media | |
| CityGro | Utah |
| CityGuyd App | Florida |
| Citynet, LLC | West Virginia |
| CityRewards, Inc. | |
| CityScope Net | Texas |
| CitySites | California |
| CitySoft, Inc. | Massachusetts |
| CitySpark | |
| CityStash | |
| CityTech Design, LLC | Delaware |
| CityWide SEO | |
| CityWideHost.com | Arizona |
| Civ Robotics, Inc. | |
| CivaTech Oncology, Inc. | North Carolina |
| Civerex Systems, Inc. | Alabama |
| CiVi Biopharma | |
| Civic Innovation Lab | California |
| Civic Mind Media, Inc. | California |
| Civic Technologies, Inc. | California |
| CivicPlus | Kansas |
| CiviCRM LLC | California |
| CIVIE | |
| CivilDesign Corporation | California |
| Civilized Software, Inc. | Maryland |
| Civis Analytics | Illinois |
| Civitas Learning, Inc. | Texas |
| Civix | Louisiana |
| CivStart | District of Columbia |
| CJ Wire & Cable Company | Texas |
| CJ's Web Services | Ohio |
| CJEN, Inc. | Virginia |
| CJR Media, Inc. | New York |
| CK Design Technology, Inc. | California |
| CK Software, Inc. | Montana |
| CKSecurity Solutions | Maryland |
| CL Creative | |
| Claflin University | South Carolina |
| Claim | |
| Claim.MD, Inc. | New Mexico |