| Sears Holdings Corporation | Hoffman Estates | 2005 |
| Sherwin-Williams | Cleveland | 1866 |
| Sinclair Broadcast Group | Hunt Valley, Cockeysville, Union Valley | 1971 |
| Six Flags | Arlington | 1961 |
| Six Flags | Charlotte | July 1, 2024 |
| Skechers | Manhattan Beach | 1992 |
| SLB | Houston | 1926 |
| SoundHound | Santa Clara | September 2005 |
| Spansion | Sunnyvale | 2003 |
| Specialized Bicycle Components | Morgan Hill | 1974 |
| Spectrum Brands | Middleton | 1906 |
| Sprint Corporation | Overland Park | 1899 |
| Standard Oil | Ohio, Cleveland, New York City | 1890 |
| Staples Inc. | Framingham | 1986 |
| Starwood | White Plains | 1930 |
| Steak 'n Shake | Indianapolis | 1934 |
| Steinway Musical Instruments | Waltham | 1995 |
| Stratolaunch Systems | Montgomery, Seattle | 2011 |
| Stüssy, Inc. | Irvine | 1980 |
| Sumisho Air Lease | Los Angeles | 2010 |
| Sunkist Growers | Los Angeles | August 29, 1893 |
| SureFire | Fountain Valley | 1979 |
| Swift Engineering | San Clemente | 1983 |
| Synopsys | Mountain View | 1986 |
| Telltale Games | San Rafael | July 2004 |
| Texaco | San Ramon | 1901 |
| The Cigna Group | Bloomfield | 1982 |
| The Hertz Corporation | Estero | 1918 |
| The Jim Henson Company | Hollywood | 1958 |
| The Kennedy/Marshall Company | Santa Monica | 1992 |
| The New York Times Company | New York Times Building, New York City | September 18, 1851 |
| The NPD Group | Port Washington | 1967 |
| The Timberland Company | Stratham | 1952 |
| The Trump Organization | Trump Tower | 1923 |
| The Vanguard Group | Malvern | May 1, 1975 |
| Theranos | Palo Alto | 2003 |
| Thermo Fisher Scientific Inc. | Waltham | 2006 |
| Time Warner Cable | New York City | 1989 |
| TJX Companies | Framingham | 1956 |
| Toro | Bloomington | 1914 |
| Tractor Supply Company | Brentwood | 1938 |
| Tripadvisor | Needham | February 14, 2000 |
| TRW Automotive | — | — |
| TRW Inc. | Euclid | 1901 |
| U.S. Cellular | Chicago | 1983 |
| U.S. Steel | Pittsburgh | 2001 |
| Ubiquiti | New York City | October 2003 |
| Ultimate Fighting Championship | Nevada, Las Vegas | 1993 |