| Silicon Graphics | Sunnyvale, Mountain View | 9 de novembro de 1981 |
| Silicon Laboratories | Austin | 1996 |
| Silver Lake | Menlo Park | 1999 |
| Sinclair Oil Corporation | Salt Lake City | 1 de maio de 1916 |
| Sirius Satellite Radio | Nova Iorque | 17 de maio de 1990 |
| Sirius XM Radio | Nova Iorque | 29 de julho de 2008 |
| Six Flags | Arlington | 1961 |
| Skechers | Manhattan Beach | 1992 |
| Skullcandy | Park City | 2003 |
| Skybound Entertainment | Beverly Hills | 1992 |
| Smith & Wesson | Springfield | 1852 |
| Smithfield Foods | Smithfield | 1936 |
| Snap Inc. | Santa Mônica, Venice | 16 de setembro de 2011 |
| SolarCity | San Mateo, Califórnia | 2006 |
| Sony Entertainment, Inc. | Nova Iorque | 2012 |
| Sony Pictures Imageworks | Vancouver, Montreal | 1992 |
| Sony Pictures Motion Picture Group | Culver City | 1998 |
| Southern Pacific Railroad | São Francisco | 1865 |
| Soylent | Los Angeles | 2013 |
| SpaceX | Starbase | 14 de março de 2002 |
| SpaceXAI | Área da baía de São Francisco | 9 de março de 2023 |
| Spansion | Sunnyvale | 2003 |
| Spectravideo | — | 1981 |
| Sports Reference | Filadélfia | 3 de dezembro de 2007 |
| Springfield Armory | Geneseo | 1974 |
| Standard Oil of Ohio | Cleveland | 1911 |
| Staples Inc. | Framingham | 1986 |
| Starkey Hearing Technologies | Eden Prairie | 1967 |
| Starwood | White Plains | 1930 |
| State Farm Insurance | Bloomington | 1922 |
| Steak 'n Shake | Indianápolis | 1934 |
| Steelcase | Grand Rapids | 1912 |
| Stellantis North America | Chrysler Headquarters and Technology Center | 28 de abril de 2009 |
| Stinson | Dayton | 1920 |
| Storage Technology Corporation | Louisville | 1969 |
| Strategic Simulations | Sunnyvale | 1979 |
| Stratfor | Austin | 1996 |
| Stripe | São Francisco, South San Francisco | 2010 |
| StumbleUpon | São Francisco | 2001 |
| Substack | — | 29 de novembro de 2017 |
| Sumisho Air Lease | Los Angeles | 2010 |
| Sunkist Growers | Los Angeles | 29 de agosto de 1893 |
| SunPower | São José | 1985 |
| Supreme | Nova Iorque | abril 1994 |
| Synaptics | Santa Clara | 1986 |
| T-Mobile US | Bellevue | 2001 |
| T. Rowe Price | Baltimore | 1937 |
| Taser International | Scottsdale | setembro 1993 |