| U Construction | Leon Susana De | — | (510) 391 1145 | GC, remodel, ADU | Union City · Alameda County | — | — |
| U G Bay Electric INC | Yener Uriel Garcia Luis | — | (213) 804 0182 | Electricians | Oakland · Alameda County | — | — |
| U H Construction | Benjamin Seiji Brunetti | — | (925) 209 4030 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| U S G A INC | Kevin Glen Youngblood | — | (925) 427 7201 | Windows, patio, painters | Livermore · Alameda County | — | — |
| U S Granite Ii | Michael William Hines | — | (510) 300 8980 | Other | Hayward · Alameda County | — | — |
| U S M I | William Chungku Lim | — | (510) 251 2929 | Other | Oakland · Alameda County | — | — |
| U S Tile & Granite | U S Tile & Granite | — | (510) 541 0502 | Other | Hayward · Alameda County | — | — |
| U S Window Renewal INC | Michael Anthony Castricone | — | (510) 769 1546 | Windows, patio, painters | Alameda · Alameda County | — | — |
| U Unlimited INC | Eitan Ben-Dov Spanier | sales@u-unlimited.com | (510) 684 8792 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| U W A Electric INC | Samuel Aibuedefe Oghogho | — | (510) 543 6886 | Electricians | Oakland · Alameda County | — | — |
| U-land Construction INC | Jim Lin | — | (415) 867 7366 | GC, remodel, ADU | Castro Valley · Alameda County | — | — |
| U-save Termite And Construction | Michael Anthony Funaro | — | (510) 472 2000 | Electricians | San Leandro · Alameda County | — | — |
| Ug Construction Group LLC | Charnvit Fuller | — | (719) 799 8999 | GC, remodel, ADU | Union City · Alameda County | — | — |
| Ugi Siding Installation | Ugi Siding Installation | — | (510) 396 7613 | Windows, patio, painters | Hayward · Alameda County | — | — |
| Ukiyo Property Management Inc. | Ukiyo Property Management Inc. | — | (510) 900-5551 | Property managers | Oakland · Alameda County | — | — |
| Uleakifix Plumbing | Uleakifix Plumbing | — | (510) 384 2593 | Other | Alameda · Alameda County | — | — |
| Ulloa's Drywall | Ulloa's Drywall | — | (510) 967 8042 | Other | Oakland · Alameda County | — | — |
| Ultimate Concrete Construction INC | Pena Abraham Rosas | info@ultimateconcreteconstruction.com | (510) 825 7063 | Other | Hayward · Alameda County | — | — |
| Ultimate Home Performance | Bachi Brunato | — | (510) 936 1212 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Ultimate Kleen Solutions | Ultimate Kleen Solutions | — | (800) 766 4356 | Other | Oakland · Alameda County | — | — |
| Underground Rooter | Underground Rooter | undergroundrooter21@gmail.com | (510) 866 5157 | Other | Oakland · Alameda County | — | — |
| Underwater Resources INC | Thomas Richard Belcher | — | (510) 957 5097 | Other | San Leandro · Alameda County | — | — |
| Uneda Glass & Window Co | Simien Lawrence | — | (510) 547 4858 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| Unfinished Business | Unfinished Business | — | (510) 520 2872 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Unhique Construction INC | Nhi Hai Nguyen | — | (510) 919 4577 | GC, remodel, ADU | Hayward · Alameda County | — | — |
| Union Remodeling INC | Manankumar Bipinchandra Trivedi | — | (510) 571 9822 | GC, remodel, ADU | Union City · Alameda County | — | — |
| Unique Environments | Douglas Wayne Bury | — | (925) 449 4588 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Unison Properties | Unison Properties | — | (510) 589 1318 | GC, remodel, ADU | Berkeley · Alameda County | — | — |
| Unistar X Construction LLC | Rajvir Singh Parmar | — | (669) 265 9498 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| United Acoustics | Rhonda Lee Kegg | — | (510) 635 3154 | Other | San Leandro · Alameda County | — | — |
| United C Construction INC | Robert Craig Allen | — | (415) 637 5517 | GC, remodel, ADU | Oakland · Alameda County | — | — |
| United Front Roofing LLC | Nestor Daniel Nunez | — | (510) 480 8773 | Other roofers | Oakland · Alameda County | — | — |
| United Misc & Ornamental Steel INC | Jose Alfredo Barrera | — | (510) 429 8755 | Other | Union City · Alameda County | — | — |
| United Royal Construction | Teon Raymond | — | (510) 468 7026 | GC, remodel, ADU | Fremont · Alameda County | — | — |
| United Underground And Overland Engineering Solutions INC | Carlos Hector Yboa | — | (408) 718 4723 | Other | Hayward · Alameda County | — | — |
| Universal Cell Site Services INC | Roberto Simbulan Galicha | — | (925) 980 2799 | GC, remodel, ADU | Livermore · Alameda County | — | — |
| Universal Construction | Diep Tan Nguyen | — | (510) 440 0837 | Electricians | Fremont · Alameda County | — | — |
| Universal HVAC Service INC | Barrera Heriberto Osorio | — | (341) 258 8413 | HVAC | San Leandro · Alameda County | — | — |
| Universal Integrated Company | Sita Devi Sharma | — | (510) 825 5251 | Electricians | Fremont · Alameda County | — | — |
| Universal Painting & Decorating | Universal Painting & Decorating | — | (650) 678 0858 | Windows, patio, painters | Hayward · Alameda County | — | — |