| S&P Global | business, enterprise, public company | Rockefeller Center, New York City | — |
| Saber Interactive | video game developer | Fort Lauderdale, Minsk, Sundsvall, Porto, Millburn, Community of Madrid, Saint Petersburg, Florida | 2001 |
| SAE International | engineering society, regulatory college, standards organization, business, company, academic publisher | Warrendale | 1905 |
| Safeway | supermarket chain, business, enterprise, public company | Pleasanton | 1915 |
| Sage Publishing | book publisher, open-access publisher, academic publisher | Thousand Oaks | 1965 |
| Sahara Las Vegas | skyscraper, hotel, casino hotel, music venue | — | 1952 |
| Saint Joseph Higher Secondary School | college | — | 1954 |
| Saint Peter's University | private not-for-profit educational institution, university | Jersey City | 1872 |
| Saint Vladimir's Orthodox Theological Seminary | private not-for-profit educational institution, seminary, university | — | 1938 |
| Saks Fifth Avenue | business | New York City | 1898 |
| Salesforce | software company, technology company, software developer, business, enterprise, public company | Salesforce Tower, San Francisco | February 3, 1999 |
| Sam Houston State University | public educational institution of the United States, university | — | 1879 |
| Sam's Club | supermarket chain | Bentonville | 1983 |
| San Francisco Museum of Modern Art | nonprofit organization, art museum, publishing house, museum, museum of modern art | San Francisco | 1935 |
| San Francisco Opera | nonprofit organization, opera company | San Francisco | 1923 |
| San Francisco Unified School District | school district in the United States | — | 1851 |
| Sanmina Corporation | business, public company | San Jose | 1980 |
| Santa Monica College | community college, college, public educational institution of the United States | Santa Monica | 1929 |
| Santa Monica Studio | video game developer | Playa Vista | 1999 |
| Sanzaru Games | video game developer | Foster City, California | 2007 |
| Saucony | business, subsidiary company | Lexington | 1898 |
| Scale AI | technology company | San Francisco | 2016 |
| Schneider's Bakery | television production company | Los Angeles | June 6, 1996 |
| Scholastic Corporation | media distributor, book publisher, business, education company, public company | New York City, Scholastic Building | 1920 |
| Schomburg Center for Research in Black Culture | library branch, creative residency, research library, public library, library building | — | 1925 |
| School of Visual Arts | private for-profit educational institution, art academy, university | New York City | 1947 |
| Schweizer Aircraft Corporation | former entity, organization, business | Horseheads, New York City | 1939 |
| Schwinn Bicycle Company | business | Chicago | 1895 |
| Scribd | online service, organization, business | San Francisco | March 2006 |
| Scripps-Booth | business, enterprise, automobile manufacturer | Detroit | 1913 |
| Scuderia Cameron Glickenhaus | automobile manufacturer | Sleepy Hollow | 2004 |
| Sears | business, public company | Hoffman Estates | 1892 |
| Seattle Central Library | library, library building | — | May 23, 2004 |
| Seattle Computer Products | business | Seattle | 1979 |
| Seattle's Best Coffee | business | Seattle | 1991 |
| SeaWorld | business, chain | Orlando | March 21, 1964 |
| SeaWorld Orlando | marine mammal park, animal theme park | — | December 15, 1973 |
| Selig Polyscope Company | film production company | Los Angeles | 1896 |
| Selznick International Pictures | film production company, film studio | Los Angeles | 1935 |
| Semrush | brand, business, public company | Boston | August 3, 2008 |
| Servant Air | airline | Kodiak | 2003 |
| Sesame Workshop | production company, nonprofit organization | 1 Lincoln Plaza, New York City | May 20, 1968 |
| Shaba Games | business | San Francisco | 1997 |
| Shimmer Women Athletes | business, enterprise | Illinois, Chicago, Berwyn | November 6, 2005 |
| Shiny Entertainment | video game developer, business | Laguna Beach, Newport Beach | 1993 |
| ShondaLand | television production company | Los Angeles | 2005 |
| Showtime | production company, film production company, cable channel, specialty channel, subscription television | New York City | July 1, 1976 |
| Shrine Auditorium and Expo Hall | auditorium, function hall, theatre building, movie theater | — | 1925 |
| Shudder | dot-com company, video streaming service | New York City | 2015 |
| Shure | business, enterprise | Niles | 1925 |
| Shuttle America | airline | Indianapolis | 1998 |
| Sierra Nevada Corporation | business | Sparks | 1963 |
| Sigma-Aldrich | business, enterprise, public company, biotechnology company | St. Louis | 1976 |
| Signetics | integrated device manufacturer | Sunnyvale | 1961 |
| Sikorsky Aircraft Corporation | aerospace manufacturer | Stratford, Connecticut | 1923 |
| Silver Airways | airline | Fort Lauderdale–Hollywood | 2011 |
| Similarweb | website, business, public company | Givatayim | 2007 |
| Simplot | business | Boise | 1929 |
| Sinclair Broadcast Group | business, enterprise, public company | Hunt Valley, Cockeysville, Union Valley | 1971 |
| Sinclair Oil Corporation | business, gas station chain | Salt Lake City | May 1, 1916 |
| Sirius Satellite Radio | former entity, business, company | New York City | May 17, 1990 |
| Six Flags | business, enterprise, public company | Arlington | 1961 |
| Six Flags Great Adventure | animal theme park | — | July 1, 1974 |
| Six Flags Magic Mountain | amusement park | — | 1971 |
| Skadden, Arps, Slate, Meagher & Flom | law firm | 1 Manhattan West | 1948 |
| Skechers | business, enterprise, public company | Manhattan Beach | 1992 |
| Skidmore, Owings and Merrill | architectural firm | Chicago | 1936 |
| Skullcandy | business, public company | Park City | 2003 |
| Sky & Telescope | business, scientific journal | — | 1941 |
| Skybound Entertainment | business | Beverly Hills | 1992 |
| Skydance Direct-to-Consumer | media company | San Francisco | April 12, 2007 |
| Slack Technologies | business, public company | San Francisco | 2009 |
| Sledgehammer Games | video game developer | Foster City | 2009 |
| Slots-A-Fun Casino | casino | — | August 5, 1971 |
| Smashburger | restaurant chain | Denver | 2007 |
| Smith & Wesson | business, enterprise, public company | Springfield | 1852 |
| Smithfield Foods | business, enterprise, public company | Smithfield | 1936 |
| Society for Industrial and Applied Mathematics | mathematical society, nonprofit organization, publishing house, source of information, learned society | University City | 1951 |
| Society of Biblical Literature | organization, open-access publisher, scientific society, learned society | Atlanta | 1880 |
| Society of Petroleum Engineers | engineering society, nonprofit organization, professional association, academic publisher | Richardson, Texas, United States | October 6, 1957 |
| Soka University of America | private not-for-profit educational institution, higher education institution, school | Aliso Viejo | 2001 |
| Sonoma State University | public educational institution of the United States, university, census-designated place in the United States | — | 1960 |
| Sonos | business, enterprise, public company | Santa Barbara | 2002 |
| 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 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 Television | television production company, division | Culver City | September 16, 2002 |
| Soros Fund Management | privately held company | New York City | — |
| SoundHound | music recognition software, enterprise, public company | Santa Clara | September 2005 |
| Southeastern Louisiana University | public educational institution of the United States, university | — | 1925 |
| Southern Air | cargo airline, airline | Norwalk | 1947 |
| Southern California Institute of Architecture | architecture school, private not-for-profit educational institution, university | — | 1972 |
| Southern Company | energy company, business, enterprise, public company | Atlanta | 1945 |
| Southern Connecticut State University | public educational institution of the United States, university | New Haven | 1893 |
| Southern Illinois University | state university system | — | 1869 |
| Southwest Airlines | airline, business, public company | Dallas | 1967 |
| Soylent | brand, business, drink mix, meal replacement | Los Angeles | 2013 |
| SpaceXAI | holding company, business | San Francisco Bay Area | March 9, 2023 |
| Specialized Bicycle Components | bicycle manufacturer, business, enterprise | Morgan Hill | 1974 |
| Spector | business | Saugerties | 1976 |
| Spectrum HoloByte | video game developer | Alameda | 1983 |
| SpinLaunch | launch service provider, space company | Long Beach | October 28, 2014 |
| Splunk Inc. | software company, enterprise, public company | San Francisco | 2004 |
| Springer Publishing | publishing house | New York City | 1950 |
| Springer Science+Business Media | book publisher, publishing house, academic publisher | Luxembourg | May 10, 1842 |
| Springfield Armory | business | Geneseo | 1974 |
| Springfield College | private not-for-profit educational institution | Springfield | 1885 |
| Sprint Corporation | mobile network operator, business, enterprise, public company | Overland Park | 1899 |
| Sprouts Farmers Market | supermarket chain, business, health food store chain, public company | Phoenix | July 2002 |
| Spyglass Media Group | film production company | Los Angeles | 1998 |
| SRI International | nonprofit organization, research institute, business | Menlo Park | 1946 |
| St. Lawrence University | private not-for-profit educational institution, liberal arts college in the United States, private university | Canton | 1856 |
| Stage 6 Films | business | Culver City | 2007 |
| Standard Oil of Ohio | business, gas station chain | Cleveland | 1911 |
| Stanford University Press | book publisher, publishing house, university press | Redwood City | 1892 |
| Stanley Motor Carriage Company | automobile manufacturer | Newton | 1902 |
| Staples Inc. | business, retail chain, enterprise, public company | Framingham | 1986 |
| Starbucks | café chain | Seattle | March 30, 1971 |
| Stellantis North America | business, enterprise, automobile manufacturer | Chrysler Headquarters and Technology Center | April 28, 2009 |
| Stony Brook University | research university, public educational institution of the United States, public university | Stony Brook University | September 16, 1957 |
| Strand Bookstore | book vendor | — | 1927 |
| Strategic Simulations | video game publisher, video game developer, business, enterprise | Sunnyvale | 1979 |
| Strategy | software company, business, public company | Tysons | 1989 |
| Stratton Oakmont | brokerage firm | Lake Success | 1988 |
| Studebaker | business, automobile manufacturer | South Bend | 1852 |
| Studebaker-Packard Corporation | automobile manufacturer | Detroit | 1954 |
| StumbleUpon | website, business | San Francisco | 2001 |
| STX Entertainment | film production company, film distributor, public company | Burbank | March 10, 2014 |
| Substack | website, publishing platform, business, podcast hosting service, enterprise, service | — | November 29, 2017 |
| Sucker Punch Productions | video game developer | Bellevue | October 1997 |
| Suffolk University | private not-for-profit educational institution, private university | Boston | 1906 |
| SugarCRM | free software, business | Cupertino | 2004 |
| Summit Entertainment | film production company | Universal City | July 26, 1991 |
| Sun Microsystems | software company, academic spin-off, business, public company | Santa Clara | February 24, 1982 |
| Supreme | apparel brand, business, enterprise | New York City | April 1994 |
| SureFire | business, enterprise | Fountain Valley | 1979 |
| SurveyMonkey | customer experience management, software as a service, service on Internet, trademark, enterprise feedback management, online survey service, market research and public opinion polling, business, Customer experience systems, public company, market research | San Mateo | 1999 |
| Swarthmore College | liberal arts college, private not-for-profit educational institution | — | 1864 |
| Swift Engineering | business, enterprise, aerospace manufacturer | San Clemente | 1983 |
| Sylvania Electric Products | organization, enterprise | — | 1942 |