| #1 Door Stop INC | Freitas Susana De | — | (209) 647 2853 | Other | Manteca · San Joaquin County | — | — |
| 1 Nation Construction INC | Robert Anthony Shea | — | (209) 406 4632 | GC, remodel, ADU | Stockton · San Joaquin County | — | — |
| 100 Degree Mechanical | 100 Degree Mechanical | — | (209) 278 7271 | HVAC | Stockton · San Joaquin County | — | — |
| 1st Class Blinds And Shutters | 1st Class Blinds And Shutters | — | (209) 838 8278 | Other | Escalon · San Joaquin County | — | — |
| 1st Class Plumbing And Drains LLC | Carlos L Del Toro | — | (510) 220 8523 | Other | Tracy · San Joaquin County | — | — |
| 1st Light Sales Corp | Justin Kenneth Krum | — | (209) 456 5415 | Electricians | Manteca · San Joaquin County | — | — |
| 209 Lath & Plastering | 209 Lath & Plastering | — | (209) 401 3849 | Other | Stockton · San Joaquin County | — | — |
| 209 Plumbing | 209 Plumbing | — | (209) 687 4367 | Other | Ripon · San Joaquin County | — | — |
| 3 B Construction INC | Jason Allan Burden | — | (209) 601 6716 | Electricians | Manteca · San Joaquin County | — | — |
| 3 Phaze Electric | Thomas Oc | — | (408) 591 5545 | Electricians | Manteca · San Joaquin County | — | — |
| 360 Elite Builders INC | Alen Truong | — | (209) 475 8323 | GC, remodel, ADU | Stockton · San Joaquin County | — | — |
| 3D Diaz Painting LLC | Jacqueline Diaz | — | (408) 483 3033 | Windows, patio, painters | Tracy · San Joaquin County | — | — |
| 3Z Electric | Brian Matthew Zumwalt | — | (209) 608 7040 | Electricians | Tracy · San Joaquin County | — | — |
| 4 Diamond Construction INC | Vincent Mario Franco | todd@diamond-construction.com | (513) 519-7766 | GC, remodel, ADU | Ripon · San Joaquin County | — | — |
| 4 G Heating & Air | 4 G Heating & Air | — | (209) 594 5392 | HVAC | Manteca · San Joaquin County | — | — |
| 4 Guys Remodeling INC | Lugo Alejandro Alamilla | — | (925) 785 4216 | GC, remodel, ADU | Tracy · San Joaquin County | — | — |
| 4 J Sectional Doors | 4 J Sectional Doors | — | (925) 383 8428 | Other | Ripon · San Joaquin County | — | — |
| 4G Concrete Specialties INC | Kristin Julia Paulazzo | — | (925) 667 7257 | Other | French Camp · San Joaquin County | — | — |
| 5 Star Construction | Bryan Lee Davis | — | (209) 518 6139 | GC, remodel, ADU | Stockton · San Joaquin County | — | — |
| 805's Framing | 805's Framing | — | (805) 407 6841 | GC, remodel, ADU | Manteca · San Joaquin County | — | — |
| A & A Climate Controls | A & A Climate Controls | — | (209) 663 1288 | HVAC | Stockton · San Joaquin County | — | — |
| A & A Electric | Paul Eugene Agans | — | (209) 333 9306 | Electricians | Acampo · San Joaquin County | — | — |
| A & E Rodriguez LLC DBA Cecil Gunite | Alonso Ortega Rodriguez | — | (209) 462 2832 | Pool | Stockton · San Joaquin County | — | — |
| A & F Construction | Alejandro Arroyo Avina | impallari@gmail.com | (209) 663 8588 | GC, remodel, ADU | Acampo · San Joaquin County | — | — |
| A & M Tile Company | Raymond Lee Jr Ausban | — | (209) 481 5929 | Other | Stockton · San Joaquin County | — | — |
| A & S Concrete | A & S Concrete | — | (209) 652 0955 | Other | Stockton · San Joaquin County | — | — |
| A & S Painting INC | Alejandro| Leon Alejandro Gutierrez Leon | — | (925) 525 8292 | Windows, patio, painters | Manteca · San Joaquin County | — | — |
| A + Heating And Air Conditioning | Michael Anese Musa Haddad | — | (209) 366 3850 | HVAC | Stockton · San Joaquin County | — | — |
| A + Painting | Edmund Daniel Townsend | — | (925) 344 2208 | Windows, patio, painters | Stockton · San Joaquin County | — | — |
| A - 1 Electrical Contractor INC | Sukhveer Singh | — | (916) 717 5968 | Electricians | Mountain House · San Joaquin County | — | — |
| A - Dependable Overhead Door Co | Christopher Michael Green | — | (209) 484 8977 | Other | Ripon · San Joaquin County | — | — |
| A - Force INC | Anthony Joseph Montantes | — | (209) 333 5296 | Windows, patio, painters | Lodi · San Joaquin County | — | — |
| A - R - M Construction | Dock Rahim Mateen | — | (209) 482 8553 | GC, remodel, ADU | Stockton · San Joaquin County | — | — |
| A - Team Construction | William Glen Garrigan | — | (209) 612 4634 | GC, remodel, ADU | Tracy · San Joaquin County | — | — |
| A 1 Landscaping | Eddie Le | — | (209) 662 1379 | Windows, patio, painters | Lathrop · San Joaquin County | — | — |
| A B C Bay Painting Co | Heon Joo Chin | — | (408) 263 0066 | Windows, patio, painters | Lathrop · San Joaquin County | — | — |
| A B Construction & Modernization | Bobby Basharat Amin | — | (209) 329 3494 | GC, remodel, ADU | Lodi · San Joaquin County | — | — |
| A B E Lath & Plastering INC | Diaz Raul Candelas | — | (209) 321 1436 | Other | Manteca · San Joaquin County | — | — |
| A B Ghio Construction INC | Anthony Bruce Ghio | — | (209) 601 2991 | GC, remodel, ADU | Stockton · San Joaquin County | — | — |
| A B Heating & Air Conditioning Services | Luong Hong Tran | — | (209) 298 1411 | HVAC | Stockton · San Joaquin County | — | — |