| Selznick International Pictures | film production company, film studio | Los Angeles | 1935 |
| Semrush | brand, business, public company | Boston | August 3, 2008 |
| Sesame Workshop | production company, nonprofit organization | 1 Lincoln Plaza, New York City | May 20, 1968 |
| Shen Yun | nonprofit organization, business | Deerpark | 2006 |
| Sheraton Hotels and Resorts | hotel chain, business | White Plains | 1937 |
| Sherwin-Williams | business, enterprise, public company | Cleveland | 1866 |
| Shiny Entertainment | video game developer, business | Laguna Beach, Newport Beach | 1993 |
| Shippensburg University of Pennsylvania | public educational institution of the United States, university | — | 1871 |
| ShondaLand | television production company | Los Angeles | 2005 |
| Showtime | business | New York City | 1983 |
| Shrine Auditorium and Expo Hall | auditorium, function hall, theatre building, movie theater | — | 1925 |
| Shuttle America | airline | Indianapolis | 1998 |
| Sierra Nevada Brewing Company | brewery | Chico | 1980 |
| Sikorsky Aircraft Corporation | aerospace manufacturer | Stratford, Connecticut | 1923 |
| Silicon Laboratories | business, public company | Austin | 1996 |
| Silver Pictures | film production company, business | Los Angeles | 1980 |
| Silvergate Capital | savings and loan association, bank, business, public company | La Jolla | 1988 |
| Similarweb | website, business, public company | Givatayim | 2007 |
| Simon & Schuster | book publisher, publishing house | New York City | 1924 |
| Sinclair Broadcast Group | business, enterprise, public company | Hunt Valley, Cockeysville, Union Valley | 1971 |
| Sir-Tech | video game developer | Ogdensburg | 1979 |
| Sirius Satellite Radio | former entity, business, company | New York City | May 17, 1990 |
| Six Flags | business, enterprise, public company | Arlington | 1961 |
| Six Flags | business, enterprise, public company | Charlotte | July 1, 2024 |
| Six Flags Magic Mountain | amusement park | — | 1971 |
| Skechers | business, enterprise, public company | Manhattan Beach | 1992 |
| Sketchfab | 3D printing marketplace, website, business | New York City | 2012 |
| Skydance Media | production company, business | Hollywood | 2006 |
| Slack Technologies | business, public company | San Francisco | 2009 |
| SLB | business, enterprise, public company, oilfield service company | Houston | 1926 |
| Slots-A-Fun Casino | casino | — | August 5, 1971 |
| Smashburger | restaurant chain | Denver | 2007 |
| Snap-on | business, public company | Kenosha | 1920 |
| Snowflake Inc. | software company, organization, business, software, public company | San Mateo | 2012 |
| Society for Industrial and Applied Mathematics | mathematical society, nonprofit organization, publishing house, source of information, learned society | University City | 1951 |
| Soka University of America | private not-for-profit educational institution, higher education institution, school | Aliso Viejo | 2001 |
| SolarCity | organization, business, subsidiary company, public company | San Mateo, California | 2006 |
| Sonoma State University | public educational institution of the United States, university, census-designated place in the United States | — | 1960 |
| Sons of the American Revolution | research library, nonprofit organization, patriotic society, museum, men's organization, charitable organization, lineage society | Louisville | April 30, 1889 |
| Sony Corporation of America | business, subsidiary company | 550 Madison Avenue, New York City | 1960 |
| Sony Entertainment | entertainment company, business | New York City | 2012 |
| Sony Imagesoft | business | Los Angeles | 1989 |
| Sony Music | major label, record company, business | New York City | January 1, 2009 |
| Sony Pictures Animation | animation studio | Culver City | 2002 |
| Sony Pictures Classics | film production company, film distributor | New York City, Los Angeles | January 1992 |
| Sony Pictures Motion Picture Group | business | Culver City | 1998 |
| SoundHound | music recognition software, enterprise, public company | Santa Clara | September 2005 |
| South Dakota State University | public educational institution of the United States, land-grant university, public research university, sun grant institution | — | 1881 |