| C R S Electric | Christopher Robin Shatterly | — | (510) 772 2334 | Electricians | Albany · Alameda County | — | — |
| C S Concrete INC | Chad Swan | impallari@gmail.com | (510) 477 8800 | Other | Union City · Alameda County | — | — |
| C S Construction | Charles Ira Seliger | — | (510) 703 9004 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| C S H Steel | C S H Steel | — | (510) 866 1778 | Other | Oakland · Alameda County | — | — |
| C S L Construction INC | Xiuhui Zheng | — | (408) 666 6847 | HVAC | Fremont · Alameda County | — | — |
| C S Z Construction Company | Can Shuang Zheng | — | (510) 717 6236 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| C V K Construction | Alexander David Korn | — | (510) 551 3384 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| C W Adams Construction INC | Clifford Wayne Adams | — | (925) 447 5736 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| C W Electric | Xiao Wei | — | (510) 866 9005 | Electricians | Castro Valley · Alameda County | — | — |
| C W Evans Painting | C W Evans Painting | — | (510) 219 5032 | Windows, patio, painters | Oakland · Alameda County | — | — |
| C W I Construction INC | Mark Douglas Wynn | — | (925) 766 5521 | Other roofers | Livermore · Alameda County | — | — |
| C Y C Commercial Wall Coverings | Cesar Cavazos | — | (510) 675 9208 | Windows, patio, painters | Hayward · Alameda County | — | — |
| C&c Property Management | C&c Property Management | — | (831) 372-1964 | Property managers | Alameda · Alameda County | — | — |
| C&l Steel INC | Jorge Luis Carrillo | — | (510) 368 9162 | Other | Hayward · Alameda County | — | — |
| C-one Flooring | Cristian Mercado | — | (510) 646 6425 | Other | Oakland · Alameda County | — | — |
| C-t Landscaping Services | Cuoc Van Tran | — | (510) 857 3122 | Windows, patio, painters | Union City · Alameda County | — | — |
| C.b Pro Inc. | Gan Hui Zheng | — | (510) 631 5838 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Ca Bear Construction | Vega-morales Oscar | info@cabearconstruction.com | (510) 900 0509 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Ca Electirc | Ca Electirc | — | (510) 755 7952 | Electricians | Union City · Alameda County | — | — |
| Ca Electrical Solutions | Mukhidinov Shamsiddin | — | (650) 787 2303 | Electricians | Union City · Alameda County | — | — |
| Ca Fifth Season Landscape | Olga Alexandrovna Androsenko | — | (925) 285 0643 | Windows, patio, painters | Fremont · Alameda County | — | — |
| Ca Heating And Air Conditioning | Ca Heating And Air Conditioning | — | (925) 905 6845 | HVAC | Livermore · Alameda County | — | — |
| Ca Painting & Decorating INC | Sanchez Ramiro Marquez | — | (510) 754 5582 | Windows, patio, painters | San Leandro · Alameda County | — | — |
| Cabinets Usa | Arnold Gregory Jr Lowenstein | — | (510) 909 0023 | Electricians | Hayward · Alameda County | — | — |
| Cable Moore INC | Gregory Clark Moore | — | (510) 866 2880 | Other | Oakland · Alameda County | — | — |
| Cabre Tech Solutions INC | Ferdinand Llamoso Aguinaldo | — | (714) 398 9792 | Electricians | Livermore · Alameda County | — | — |
| Cad Com | Cad Com | — | (510) 677 4912 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Caistor Construction | Timothy Peter Caistor | — | (510) 390 7375 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Cal - Fed Construction Company | Xueyong Mei Chen | — | (510) 388 1909 | GC, remodel, ADU | San Lorenzo · Alameda County | — | — |
| Cal - Pac Construction And Supply INC | Tian Yue Chen | — | (510) 213 4814 | Electricians | San Leandro · Alameda County | — | — |
| Cal - Safety INC | Kevin Gerard Karrick | — | (510) 656 5544 | Other | Fremont · Alameda County | — | — |
| Cal Bear Builders INC | Guerrero Ortiz Jocelin | — | (408) 469 5135 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Cal Coast Window & Door INC | Robert Allen Jr Rowe | — | (925) 398 8184 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Cal Home Solutions | Cal Home Solutions | jeff@calhomesolutions.com | (510) 825 0077 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Cal Phase Electric INC | Shawn William Hancock | — | (925) 671 9200 | Electricians | San Leandro · Alameda County | — | — |
| Cal Pro Contractors | Matthew Francis Ghiringhelli | info@calprocontractors.com | (510) 402 7092 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Cal State Pro-group INC | Estrada Alonso Lujano | — | (510) 780 2221 | GC, remodel, ADU | San Leandro · Alameda County | — | — |
| Cal Tile Company INC | Calvin Nhuoc Hong | — | (510) 749 9932 | Other | Alameda · Alameda County | — | — |
| Cal Tree Care Incorporated | Thomas James Lee | — | (510) 786 3955 | Tree | Hayward · Alameda County | — | — |
| Cal's Painting | Cal's Painting | — | (510) 730 4217 | Windows, patio, painters | Berkeley · Alameda County | — | — |