| Richard Childress Racing | — | 1969 |
| Rickenbacker | Santa Ana | 1931 |
| Rivian Automotive | Detroit | June 2009 |
| RJR Nabisco | Cobb County, Winston-Salem, New York City | April 25, 1986 |
| Rogers Locomotive and Machine Works | — | 1832 |
| Rohm and Haas | Philadelphia | September 1, 1909 |
| Roku, Inc. | Los Gatos | October 2002 |
| Rotten Tomatoes | San Francisco | August 19, 1998 |
| Rough Draft Studios | Glendale | 1990 |
| RSA | Bedford | 1986 |
| RTX | Arlington County | April 3, 2020 |
| Ryan Aeronautical | San Diego | 1934 |
| Ryder | Coral Gables | 1933 |
| S&P Global | Rockefeller Center, New York City | — |
| SAE International | Warrendale | 1905 |
| Safeway | Pleasanton | 1915 |
| Saks Fifth Avenue | New York City | 1898 |
| Salesforce | Salesforce Tower, San Francisco | February 3, 1999 |
| Sanmina Corporation | San Jose | 1980 |
| Saucony | Lexington | 1898 |
| Scholastic Corporation | New York City, Scholastic Building | 1920 |
| Schweizer Aircraft Corporation | Horseheads, New York City | 1939 |
| Schwinn Bicycle Company | Chicago | 1895 |
| Scribd | San Francisco | March 2006 |
| Scripps-Booth | Detroit | 1913 |
| Sears | Hoffman Estates | 1892 |
| Seattle Computer Products | Seattle | 1979 |
| Seattle's Best Coffee | Seattle | 1991 |
| SeaWorld | Orlando | March 21, 1964 |
| Semrush | Boston | August 3, 2008 |
| Shaba Games | San Francisco | 1997 |
| Shimmer Women Athletes | Illinois, Chicago, Berwyn | November 6, 2005 |
| Shiny Entertainment | Laguna Beach, Newport Beach | 1993 |
| Shure | Niles | 1925 |
| Sierra Nevada Corporation | Sparks | 1963 |
| Sigma-Aldrich | St. Louis | 1976 |
| Similarweb | Givatayim | 2007 |
| Simplot | Boise | 1929 |
| Sinclair Broadcast Group | Hunt Valley, Cockeysville, Union Valley | 1971 |
| Sinclair Oil Corporation | Salt Lake City | May 1, 1916 |
| Sirius Satellite Radio | New York City | May 17, 1990 |
| Six Flags | Arlington | 1961 |
| Skechers | Manhattan Beach | 1992 |
| Skullcandy | Park City | 2003 |
| Sky & Telescope | — | 1941 |
| Skybound Entertainment | Beverly Hills | 1992 |
| Slack Technologies | San Francisco | 2009 |
| Smith & Wesson | Springfield | 1852 |