| # | Company name | Role | # of projects |
|---|---|---|---|
| 1 | C E Hance | 0 | |
| 2 | Caisteal Builders Inc. | General contractor | 1 |
| 3 | California Building Evaluation | 0 | |
| 4 | City of Anaheim Public Works | Client | 1 |
| 5 | Claude K. Bell | Artist | 1 |
| 6 | Clausen Enterprises Inc. | Client | 1 |
| 7 | Clean City Inc. | General contractor | 1 |
| 8 | Consensys Property Management | Property management | 0 |
| 9 | Construction Concepts Inc | General contractor | 5 |
| 10 | Control Air Conditioning | Mechanical systems installation | 3 |
| 11 | Coorg Corporation | General contractor | 0 |
| 12 | Crandall & Sons | General contractor | 2 |
| 13 | Cretesoutheastal | Supplier | 0 |
| 14 | Ctp Construction Company Inc | General contractor | 1 |