| Oleas Painting INC | Jaime Odon Olea | — | (559) 554 6457 | Windows, patio, painters | Fresno · Fresno County | — | — |
| Oleg's Electric | Oleg Petrovich Grinyuk | — | (559) 259 2616 | Electricians | Fresno · Fresno County | — | — |
| Olive Builder INC | Munoz Alvarado Horacio | info@olivebuilder.com | (559) 421 5427 | GC, remodel, ADU | Sanger · Fresno County | — | — |
| Olman Osman Ayala Diaz | Olman Osman Ayala Diaz | — | (602) 410 4132 | GC, remodel, ADU | Fresno · Fresno County | — | — |
| Olmos Landscape And Maintenance | Olmos Landscape And Maintenance | — | (589) 259 8354 | Windows, patio, painters | Fresno · Fresno County | — | — |
| Olmos Painting Service | Olmos Telles Daniel | — | (559) 797 5592 | Windows, patio, painters | Fresno · Fresno County | — | — |
| Olmsted Painting | Olmsted Painting | — | (559) 246 2777 | Windows, patio, painters | Fresno · Fresno County | — | — |
| Olsen Construction And Restoration Co | Blair Ralph Olsen | — | (559) 266 3473 | GC, remodel, ADU | Fresno · Fresno County | — | — |
| Olson Wagner Construction INC | Martin Jay Olson | office@olsonwagner.com | (559) 299 9328 | GC, remodel, ADU | Clovis · Fresno County | — | — |
| Omar Antonio Sandoval Cortes | Omar Antonio Sandoval Cortes | — | (559) 396 8042 | Electricians | Selma · Fresno County | — | — |
| Omar's Concrete | Omar's Concrete | — | (559) 666 5597 | Other | Fresno · Fresno County | — | — |
| Omega Air And Heating INC | Jamie Yoshiki Ishisaka | — | (559) 990 0090 | HVAC | Clovis · Fresno County | — | — |
| Omega Roofing Company | Issai Terrones-Padilla | jeremy@omega-roofing.com | (559) 709 3513 | Other roofers | Fresno · Fresno County | — | — |
| Omni Underground | Brett William Brewer | brett@omniundergroundinc.com | (559) 567 5626 | Other | Clovis · Fresno County | — | — |
| On Call Electrical | On Call Electrical | — | (559) 900-3111 | Electricians | Fresno · Fresno County | — | — |
| On Point Carpentry INC | Diaz Roberto Gonzales | — | (559) 558 7251 | Other | Fresno · Fresno County | — | — |
| On Top Roofing | Ruben Louis Dominguez | — | (559) 458 3037 | Other roofers | Fresno · Fresno County | — | — |
| One Of A Kind Services | Charles Edward Jr Mitchell | — | (559) 477 0717 | Windows, patio, painters | Sanger · Fresno County | — | — |
| Ontiveros Consulting DBA Complete Construction Company C C C | Estevan Benavides | — | (559) 536 0625 | Other roofers | Clovis · Fresno County | — | — |
| Ontrack Construction | Douglas William Mac Neill | — | (559) 908 2328 | GC, remodel, ADU | Sanger · Fresno County | — | — |
| Optimal Energy INC | Rudy Aboliso Rabino | — | (559) 375 4446 | Electricians | Sanger · Fresno County | — | — |
| Orah Electric And Construction INC | Bradley James Huxley | — | (559) 917 0479 | Electricians | Clovis · Fresno County | — | — |
| Orkin | Orkin | — | (559) 682-6001 | Pest, tile roofs | Fresno · Fresno County | — | — |
| Ornamental Steel Fabrication INC | Perez Alejandro Rosales | — | (559) 478 3447 | Other | Fresno · Fresno County | — | — |
| Ortiz Legacy Plastering INC | Kevin Bryan Ortiz Padilla | — | (559) 396 2197 | Other | Fresno · Fresno County | — | — |
| Oscar Topete Electric INC | Oscar Roel Topete | — | (559) 824 2348 | Electricians | Clovis · Fresno County | — | — |
| Oso Holding Group LLC | Steven O Spano | — | (559) 589 5984 | GC, remodel, ADU | Fresno · Fresno County | — | — |
| Osuna Omega Electric | Carlos Fernando Osuna | — | (760) 234 7584 | Electricians | Clovis · Fresno County | — | — |
| Oswaldo Sanchez DBA L W Fences | L W Fences | — | (559) 704 0223 | Other | Fresno · Fresno County | — | — |
| Outback Builders INC | Samuel Grady Robinson | — | (559) 298 8010 | GC, remodel, ADU | Clovis · Fresno County | — | — |
| Outback Concrete INC | Samuel Grady Robinson | — | (559) 298 8010 | Other | Clovis · Fresno County | — | — |
| Outback Materials | James Dustin Graham | — | (559) 293 3880 | Other | Fresno · Fresno County | — | — |
| Ovalle Tractor And Trucking | Ovalle Tractor And Trucking | — | (559) 289 5737 | Other | Clovis · Fresno County | — | — |
| Overall Painting Co | Erik Stephen Zeagler | — | (559) 387 7428 | Windows, patio, painters | Fresno · Fresno County | — | — |
| Overhead Door Company Of Fresno INC | Sara Lynn Dunshee | — | (559) 292 3366 | Other | Fresno · Fresno County | — | — |
| Oxborrow Enterprises INC | Kenneth Randall Oxborrow | — | (559) 978 5600 | Other | Coalinga · Fresno County | — | — |
| P & J Custom Window Coverings | Frank Charles Iv Spencer | — | (559) 252 0490 | Other | Fresno · Fresno County | — | — |
| P & K Grout & Sealing | Phillip Edward White | — | (559) 970 3084 | Other | Clovis · Fresno County | — | — |
| P C Construction And Maintenance | Luis Ivan Pazos Cazares | — | (559) 801 7576 | GC, remodel, ADU | Clovis · Fresno County | — | — |
| P C H Pools | P C H Pools | eben@eyebytes.com | (559) 691 6300 | Pool | Fresno · Fresno County | — | — |