| Comfort Dynamics INC | Anthony Mark De Meo | contact@comfortdynamics.com | (510) 352 8501 | HVAC | San Leandro · Alameda County | — | — |
| Comfort Interior Flooring | Comfort Interior Flooring | — | (510) 260 4028 | Other | Oakland · Alameda County | — | — |
| Comfy Heating & Air Conditioning INC | Abel Nobrega Vieira | — | (510) 317 7375 | HVAC | San Leandro · Alameda County | — | — |
| Commercial Casework Incorporated | Laura M Martin | — | (510) 657 7933 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Commercial Construction | Perri Gio | — | (415) 629 4756 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Commercial Door And Frame INC | Ronald Brian Autrand | — | (510) 957 5108 | Other | San Leandro · Alameda County | — | — |
| Commercial Glazing Concepts INC | Matija Turkalj | — | (707) 297 9901 | Windows, patio, painters | Pleasanton · Alameda County | — | — |
| Commercial Maintenance Management Services INC | Bobbie R Sage | — | (510) 828 1957 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Compactor Management Company LLC | David Lucio | — | (510) 623 2323 | Other | Union City · Alameda County | — | — |
| Compass Engineering Contractors INC | Michael Scott Moore | — | (510) 264 0225 | Other | Hayward · Alameda County | — | — |
| Complete Const Co | Robert Dean Brown | — | (510) 427 4722 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Complete Construction | Mark Ellis Feinman | paul@complete-construction.com | (510) 528 8800 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Complete Property Development | Complete Property Development | — | (510) 325 7462 | Electricians | Berkeley · Alameda County | — | — |
| Complete Siding Solutions | Complete Siding Solutions | jgonzalez@complete-siding-solutions.com | (650) 743 4433 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Comtel Systems Technology INC | Jason Christopher Hughes | — | (408) 543 5600 | Electricians | Pleasanton · Alameda County | — | — |
| Concept Builders Cj INC | Solorzano Cesar Mendoza | — | (510) 980 3594 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Concept Construction | Buyandalai Badral | — | (415) 378 8780 | GC, remodel, ADU | Alameda · Alameda County | — | — |
| Concrete Wall Sawing Co INC | Kenyon Corbett Barnes | — | (510) 483 8440 | Other | San Lorenzo · Alameda County | — | — |
| Concrete Work INC | Jose Andres Tapia-Uraga | — | (510) 316 5300 | Windows, patio, painters | San Leandro · Alameda County | — | — |
| Concreteworks Studio INC | Mark A Rogero | — | (510) 534 7141 | Other | San Leandro · Alameda County | — | — |
| Condon-johnson & Associates INC | Keith Stephen Bizzack | — | (510) 636 2100 | Other | Oakland · Alameda County | — | — |
| Condylis Baier Design Build | Daniel Mark Condylis | — | (415) 757 7847 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Conflo Services INC | Daniel Serge Levine | info@confloservices.com | (510) 732 6695 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Cong Van Phan | Cong Van Phan | — | (510) 378 4856 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Connected Electrician | Connected Electrician | steve@connected-electrician.com | (510) 812 9073 | Electricians | Oakland · Alameda County | — | — |
| Connell Electric | Kevin Joseph Connell | — | (510) 364 1758 | Electricians | Hayward · Alameda County | — | — |
| Consolidated Cm | Scott Stanley Ritter | yccm@consolidatedcm.com | (510) 208 1720 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Consolidated Partitions Incorporated | Wallie Steinorth | — | (510) 352 3920 | Other | Hayward · Alameda County | — | — |
| Constanza Construction | Garcia Constanza Leonardo | — | (510) 934 3584 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Construct-zion INC | Alvarez Oswaldo Ventura | — | (510) 823 2421 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Construction & More | Philip Liljenskjold Alne | — | (619) 317 8159 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Construction Management Associates | Omar Jr Hindiyeh | — | (925) 456 8000 | Other roofers | Livermore · Alameda County | — | — |
| Construction Remodeling In Bay Area INC | Ershad Mandegari | — | (415) 490 6654 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Construmath Builder | Construmath Builder | — | (510) 943 7188 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Contract Floor Coverings INC | James Dean Smith | — | (925) 292 0600 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Conxtech INC | Conxtech INC | info@conxtech.com | (510) 264 9111 | Other | Pleasanton · Alameda County | — | — |
| Cool Painting INC | Patrick Gerard Cool | — | (415) 359 4556 | Windows, patio, painters | Dublin · Alameda County | — | — |
| Cooper And Hawkins Incorporated | Steven Alden Cooper | — | (510) 845 4225 | HVAC | Berkeley · Alameda County | — | — |
| Cooper Construction And Engineering INC | Leduval | — | (510) 415 3654 | Other | Oakland · Alameda County | — | — |
| Cooper Electrical | David Lee Cooper | — | (510) 862 2060 | Electricians | Alameda · Alameda County | — | — |