| Silicon Laboratories | Austin | 1996 |
| Silvergate Capital | La Jolla | 1988 |
| Similarweb | Givatayim | 2007 |
| Simplot | Boise | 1929 |
| Sinclair Oil Corporation | Salt Lake City | 1 de maio de 1916 |
| Singularity University | Mountain View | 2010 |
| SiRF | São José | 1995 |
| Sirius Satellite Radio | Nova Iorque | 17 de maio de 1990 |
| Sirius XM Radio | Nova Iorque | 29 de julho de 2008 |
| Sketchfab | Nova Iorque | 2012 |
| Skullcandy | Park City | 2003 |
| Skybound Entertainment | Beverly Hills | 1992 |
| Skydance Media | Hollywood | 2006 |
| Smith & Wesson | Springfield | 1852 |
| Smithfield Foods | Smithfield | 1936 |
| SolarCity | San Mateo, Califórnia | 2006 |
| Sonos | Santa Bárbara | 2002 |
| Sony Corporation of America | Sony Building, Nova Iorque | 1960 |
| Sony Pictures Motion Picture Group | Culver City | 1998 |
| Southern Company | Atlanta | 1945 |
| Southern Pacific Railroad | São Francisco | 1865 |
| Southwest Airlines | Dallas | 1967 |
| Soylent | Los Angeles | 2013 |
| SpaceX | Starbase | 14 de março de 2002 |
| Spanx | Atlanta | 2000 |
| Specialized | Morgan Hill | 1974 |
| Sports Reference | Filadélfia | 3 de dezembro de 2007 |
| Sprint Nextel | Overland Park | 1899 |
| Sprouts Farmers Market | Phoenix | julho 2002 |
| Stage 6 Films | Culver City | 2007 |
| Standard Oil Company | Ohio, Cleveland, Nova Iorque | 1890 |
| State Farm Insurance | Bloomington | 1922 |
| State Street Corporation | Boston | 1792 |
| Steinway Musical Instruments | Waltham | 1995 |
| Stellantis North America | Chrysler Headquarters and Technology Center | 28 de abril de 2009 |
| Stinson | Dayton | 1920 |
| Stratfor | Austin | 1996 |
| Stripe | São Francisco, South San Francisco | 2010 |
| Studebaker | South Bend | 1852 |
| Stüssy, Inc. | Irvine | 1980 |
| Substack | — | 29 de novembro de 2017 |
| SugarCRM | Cupertino | 2004 |
| Sumisho Air Lease | Los Angeles | 2010 |
| Sun Microsystems | Santa Clara | 24 de fevereiro de 1982 |
| Supermicro | São José | 1993 |
| Synopsys | Mountain View | 1986 |
| System 76 | Denver | 7 de novembro de 2005 |
| T-Mobile US | Bellevue | 2001 |