| Scholastic Corporation | New York City, Scholastic Building | 1920 |
| Schweizer Aircraft Corporation | Horseheads, New York City | 1939 |
| Scribd | San Francisco | March 2006 |
| SDI Media Group | Culver City | 1965 |
| Seabourn Cruise Line | Seattle, Miami | 1986 |
| Seagate Technology | Cupertino | 1979 |
| Sears | Hoffman Estates | 1892 |
| Seattle Computer Products | Seattle | 1979 |
| Seeburg Corporation | Chicago | 1902 |
| Sekai Project | Norwalk, Los Angeles | 2007 |
| Shaba Games | San Francisco | 1997 |
| Shimmer Women Athletes | Illinois, Chicago, Berwyn | November 6, 2005 |
| Shiny Entertainment | Laguna Beach, Newport Beach | 1993 |
| Shure | Niles | 1925 |
| Shutterstock | New York City, Empire State Building | 2003 |
| Sierra Nevada Corporation | Sparks | 1963 |
| Silver Lake | Menlo Park | 1999 |
| Silvergate Capital | La Jolla | 1988 |
| Sinclair Broadcast Group | Hunt Valley, Cockeysville, Union Valley | 1971 |
| Sinclair Oil Corporation | Salt Lake City | May 1, 1916 |
| Skybound Entertainment | Beverly Hills | 1992 |
| Skydance Media | Hollywood | 2006 |
| Skywalker Sound | Lucas Valley | 1975 |
| SLB | Houston | 1926 |
| Snap-on | Kenosha | 1920 |
| Sonos | Santa Barbara | 2002 |
| Sony Pictures Motion Picture Group | Culver City | 1998 |
| Southern Company | Atlanta | 1945 |
| SpaceX | Starbase | March 14, 2002 |
| Specialized Bicycle Components | Morgan Hill | 1974 |
| Spectrum Brands | Middleton | 1906 |
| Sports Reference | Philadelphia | December 3, 2007 |
| Springfield Armory | Geneseo | 1974 |
| Sprint Corporation | Overland Park | 1899 |
| SSC North America | West Richland | 1999 |
| Standard Oil of Ohio | Cleveland | 1911 |
| Stanley Black & Decker | New Britain | 1843 |
| Staples Inc. | Framingham | 1986 |
| Starkey Hearing Technologies | Eden Prairie | 1967 |
| Starwood | White Plains | 1930 |
| State Farm Insurance | Bloomington | 1922 |
| State Street Corporation | Boston | 1792 |
| Steak 'n Shake | Indianapolis | 1934 |
| Steelcase | Grand Rapids | 1912 |
| Stepan Company | Northfield | 1932 |
| Strategic Simulations | Sunnyvale | 1979 |
| Strategy | Tysons | 1989 |
| Stratolaunch Systems | Montgomery, Seattle | 2011 |