| Ya Homes INC | Yumo Liu | — | (408) 876 0886 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Yabusaki's Landscape Services | Kenneth Keigi Yabusaki | — | (510) 332 3884 | Windows, patio, painters | Berkeley · Alameda County | — | — |
| Yada Signs | Yada Signs | — | (510) 828 9354 | Other | Hayward · Alameda County | — | — |
| Yang's Remodeling LLC | Frank Yang | — | (925) 621 9771 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Yanscape Design | Anthony Tong Yu Yan | — | (510) 908 1100 | Electricians | Alameda · Alameda County | — | — |
| Yantong Liang Construction | Liang Yantong | — | (510) 493 6558 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Yao Guo Mai | Yao Guo Mai | — | (415) 298 1650 | Windows, patio, painters | San Leandro · Alameda County | — | — |
| Yao Hai Construction Company | Qin Yao Hai | — | (510) 508 2811 | GC, remodel, ADU | Alameda · Alameda County | — | — |
| Yard Duty LLC | Roberto Valencia | — | (510) 398 9735 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Yates Restoration INC | Phillip Francis Schanbacher | impallari@gmail.com | (928) 927 1500 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Yazolino Construction | Gary Paul Yazolino | — | (510) 995 8991 | GC, remodel, ADU | Alameda · Alameda County | — | — |
| Yee Cheung | Yee Cheung | — | (925) 586 4321 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| Yelcon Development | Yelcon Development | — | (925) 580 9943 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Yen Lin Li Company INC | Yen Lin Li | — | (510) 534 4296 | HVAC | Oakland · Alameda County | — | — |
| Yes Construction Group INC | Xiu Ting Zhang | — | (510) 261 2000 | Electricians | Oakland · Alameda County | — | — |
| Yi Min Zheng | Yi Min Zheng | — | (415) 519 9757 | GC, remodel, ADU | San Lorenzo · Alameda County | — | — |
| Yin Ng | Yin Ng | — | (510) 396 8388 | Electricians | Fremont · Alameda County | — | — |
| Yings Construction | Ying Tina | — | (510) 585 7889 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yip & Associated | Yip & Associated | — | (510) 333 7389 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Yjv Stainless INC | Jaime Ortega | — | (510) 432 9338 | Other | Hayward · Alameda County | — | — |
| Yoda Painting INC | Takar Mutlu | yodapainting@gmail.com | (415) 375 1611 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Yong Hong Construction INC | Herman He Xin Kuang | — | (510) 723 0088 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Yong's Painting | Yong's Painting | — | (925) 819 1485 | Windows, patio, painters | Dublin · Alameda County | — | — |
| Yongqi Lin | Yongqi Lin | — | (415) 640 9764 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yori Landscape Incorporated | Norman Kiyoshi Jr Yoritate | — | (510) 659 1736 | Windows, patio, painters | Fremont · Alameda County | — | — |
| Yorkshire Roofing Of Northern California INC DBA Roofmax | Kenneth Edward Falconi | — | (925) 606 6700 | Other roofers | Livermore · Alameda County | — | — |
| You & Yu Development | You & Yu Development | — | (510) 388 5787 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Young P Hur | Young P Hur | — | (408) 616 0922 | Electricians | Pleasanton · Alameda County | — | — |
| Young's Lock & Key | Young's Lock & Key | — | (510) 909 5128 | Other | San Leandro · Alameda County | — | — |
| Your Carpenter Friend | Your Carpenter Friend | — | (510) 353 3735 | Other | Castro Valley · Alameda County | — | — |
| Your Energy Solutions | Louay George Zughbaba | — | (650) 771 0700 | Other roofers | Livermore · Alameda County | — | — |
| Your Go 2 Handyman | Your Go 2 Handyman | — | (510) 386 8361 | GC, remodel, ADU | Newark · Alameda County | — | — |
| Your Warm Friend INC DBA Atlas Heating & Air-conditioning Co | Robert Douglas Tuck | — | (510) 893 1343 | HVAC | Oakland · Alameda County | — | — |
| Yours Construction INC | Mario Haristarco Hernandez | — | (510) 325 1710 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yu Canqin Construction | Yu Canqin | — | (628) 228 7324 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Yu Chuck Huangli | Yu Chuck Huangli | — | (510) 423 1423 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yu Peihao | Yu Peihao | — | (510) 770 7616 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yuching Lin | Yuching Lin | — | (510) 493 8468 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| Yudu Sun | Yudu Sun | — | (650) 338 8600 | GC, remodel, ADU | Pleasanton · Alameda County | — | — |
| Yuehuan Xu | Yuehuan Xu | — | (510) 458 7016 | GC, remodel, ADU | Fremont · Alameda County | — | — |