| Cipher | |
| Cipher Pharmaceuticals, Inc. | |
| Cipher Surgical Ltd | |
| Cipher Systems | Tennessee |
| CipherCloud, Inc. | California |
| CipherHealth, Inc. | New York |
| CipherIO | |
| Cipherlogic | |
| Cipherome, Inc. | California |
| Ciphers Digital | |
| CipherTechs | Illinois |
| CipherTrace | California |
| CIPPlanner Corporation | California |
| CIQ, Inc. | Nevada |
| Ciqur24 | Wyoming |
| Cirba Solutions | North Carolina |
| CiRC Biosciences | Illinois |
| Circa Design Company | South Dakota |
| Circadence | Colorado |
| Circadian Digital, LLC | |
| Circana | |
| Circle Commerce, Inc. | Connecticut |
| Circle Computer Resources, Inc. | Iowa |
| Circle Internet Group, Inc. | |
| Circle Internet Services, Inc. | California |
| Circle Pharma | |
| Circle R Designs | California |
| Circle Studios | Virginia |
| Circle Twelve, Inc. | Massachusetts |
| Circleback AI, Inc. | |
| CircleBlack, Inc. | Massachusetts |
| Circleboom, LLC | |
| CirclesX, LLC | |
| CircNova, Inc. | Michigan |
| Circonus, Inc. | Pennsylvania |
| Circor | |
| Circotech.com | California |
| Circuit Board Assembly Services | California |
| Circuit Design | California |
| Circuit Design Specialties, Inc. | Texas |
| Circuit Express, Inc. | California |
| Circuit ID, Inc. | |
| Circuit Interruption Technology, Inc. | Minnesota |
| Circuit Technology Center, Inc. | Massachusetts |
| Circuit Technology, Inc. | North Carolina |
| Circuit Works Corporation | Illinois |
| Circuitech | Minnesota |
| CircuitHub | |
| Circuitronics, Inc. | Texas |
| Circuits West, Inc. | Colorado |