| Rook Construction | B | 2026 | Active |
| Rossi Builders Inc | B | 1964 | Active |
| Rove Construction LLC | B | 2025 | Active |
| RS Construction Service Inc. | B | 2024 | Active |
| RSB Construction Group Inc | A, B + C10, C16, C20 +1 | 2022 | Active |
| RSJ Contracting LLC | B | 2026 | Active |
| Rua Woods Construction Inc | B | 2014 | Active |
| Rubecon Builders Inc | A, B + C5, C6, C8 +2 | 1997 | Active |
| Ruby Plumbing & Electrical Supply Inc | B + C10, C16, C36 | 1998 | Active |
| Ruiz A Construction Co & Assoc Inc | A, B | 1982 | Active |
| Ryan Build Group LLC | B | 2026 | Active |
| Ryz Electrical | B + C10, C36 | 2020 | Active |
| S & P Builder Inc | B | 2019 | Active |
| S And L Tec Construction Company Inc | B + C10 | 2009 | Active |
| S F Garage Company Inc. | A, B + C4, C10, C16 +1 | 1994 | Active |
| S F T Construction Corp | B | 2015 | Renew by Dec 31, 2026 |
| S F Town Builders Inc | B | 2014 | Active |
| S F Underground | A | 2016 | Active |
| S J K Development Inc | B | 1997 | Active |
| S L M Development Inc | B | 2004 | Active |
| S M H Builders | B | 2014 | Active |
| S W L Electric Inc | B + C10 | 2006 | Active |
| S Y Builder Inc | A, B | 2026 | Active |
| S2 / H Construction Group | A, B | 1999 | Active |
| Sage Construction Services | B | 2021 | Active |
| Saint Bridget Construction Inc | A, B | 2025 | Active |
| Sallinger Enterprises Inc | B | 2004 | Active |
| Samco Construction Inc | B + C10 | 2007 | Active |
| Samgroup Construction | A, B | 2020 | Active |
| San Francisco Design And Construction Inc | B | 2004 | Active |
| San Francisco Green Spaces | B + C27 | 2010 | Active |
| San Francisco Heating And Cooling | B + C20 | 2013 | Active |
| San Francisco Investment Development | B | 2007 | Active |
| San Francisco RG Solution | B | 2025 | Active |
| Sapphire Bay Area Construction Inc | B | 2023 | Active |
| Sasso Construction Inc | B + C10 | 2008 | Active |
| Saturn Construction Co | B | 2005 | Active |
| Sca Environmental Inc | A + C22, HAZ | 1997 | Active |
| Scale Renovation | B2 | 2025 | Active |
| Schembri Construction Co Inc | A, B + HAZ | 2007 | Active |
| Scherer Scott Construction Inc | B + C27 | 1987 | Active |
| Schneider Design Associates Inc | B | 2004 | Renew by Dec 31, 2026 |
| Scp-Builders Inc | B | 2007 | Active |
| Seapoint Construction Inc | B | 2007 | Active |
| Sederap's Drywall Inc | B + C9, C10, C36 | 2008 | Active |
| Seiscore | A | 2024 | Active |
| Seismic Retrofitters Inc | B + C10, C36 | 1998 | Active |
| Selecta Construccion LLC | B | 2026 | Active |
| Sequoia Build Group Inc | B | 2023 | Active |
| Set Construction LLC | B | 2024 | Active |
| SF Builders Inc | B | 2017 | Active |
| SF Craftsman Inc | B | 2007 | Active |
| SF Premier Builders Inc | B | 2026 | Active |
| Sf& S Construction | A + ASB, D38, HAZ | 2015 | Active |
| SFBM Group LLC | B | 2026 | Active |
| SH Painting And Construction Inc | B + C33 | 2023 | Active |
| Shao Fat Construction Inc | B + C10 | 2005 | Active |
| Shapiro Dmitry Construction | B | 2018 | Renew by Dec 31, 2026 |
| Sheedy Drayage Co | A + D21, D36 | 1958 | Active |
| Sheeran Pipeline Inc | A | 2017 | Active |
| Shek's Construction Company Inc | B | 1979 | Active |
| Shin Engineering | A | 2009 | Active |
| Shiny Home Builders & Development Inc | B | 2024 | Active |
| Shorecal Engineering Inc | A | 2025 | Active |
| Showme Homes | B | 2020 | Active |
| Sierra Electric Co | B + C10 | 1959 | Active |
| Sierra Ridge Deck And Siding | B + D41 | 2024 | Active |
| Silva-Management And Construction Services LLC | A, B | 2022 | Renew by Dec 31, 2026 |
| Silver Lining Design Build Co | B | 2017 | Active |
| Simon & Brother Construction Inc | B | 2024 | Active |
| Simplifi | B + C7 | 2006 | Active |
| Simply Affordable Rooter Inc | B + C36 | 2016 | Active |
| Singular Builders | A, B | 2023 | Active |
| Siteco Services Inc | A + C21, HAZ | 2003 | Active |
| Skanska Suffolk A California Joint Venture | A, B | 2025 | Active |
| Skycore Construction | B | 2002 | Active |
| Skye's The Limit Construction | B | 2006 | Active |
| Skyland Construction Inc | B + C10 | 2002 | Active |
| Skyline Construction Inc | B | 1996 | Active |
| Skyline Roofing And Construction Inc | B + C39 | 2025 | Active |
| Skymark Construction Company | B | 2026 | Active |
| Skytec General Engineering | A, B + C10, C16, C20 +1 | 2023 | Active |
| Skytech Construction Inc | B + C10, C36 | 2020 | Active |
| Skyy Builders Inc | B | 2015 | Active |
| SLD Construction Inc | B | 2020 | Renew by Dec 31, 2026 |
| Sleo Construction Inc | B | 2026 | Active |
| Slick Construction Inc | B | 2018 | Active |
| Smarter Construction Inc | B | 2009 | Renew by Dec 31, 2026 |
| Solid Bay Construction SF | B | 2026 | Active |
| Soma Door & Accessories Inc | B | 2024 | Active |
| Sonhei Construction Engineering Inc | A, B + C17 | 2013 | Active |
| Sound Build | B + C2 | 2022 | Active |
| Soundproofing Remodelers | B | 2008 | Active |
| Source Planning And Construction Inc | B | 2010 | Active |
| Sparkie Solutions | B + C10 | 2026 | Active |
| Spatialities Inc | B | 2004 | Active |
| Speedy Engineering And Construction Inc | A, B + C36 | 1996 | Active |
| SPL Construction SF | B | 2009 | Active |
| Spotlight Construction Groups Inc | B + D34 | 1995 | Active |
| Springhill Homes Of California Inc | B | 2015 | Active |