| Princess Cruises | Santa Clarita | 1965 |
| Pro Wrestling Guerrilla | Sur de California | 2003 |
| Proactiv Solution | — | 1995 |
| Procter & Gamble | Ohio, Cincinnati | 31 de octubre de 1837 |
| Progressive Corporation | Mayfield | 10 de marzo de 1937 |
| Providence Equity Partners | 50 Kennedy Plaza | 1989 |
| Qorvo | Greensboro | 2015 |
| Quaker Oats Company | Chicago | 1877 |
| Quest Software | Aliso Viejo | 1987 |
| Quiksilver | Huntington Beach | 1969 |
| Radisson Hotel Group | Minnetonka | 1962 |
| Ralph Lauren Corporation | Nueva York | 1967 |
| Rambus | Sunnyvale | 1990 |
| Rand McNally | Chicago, Skokie | 1856 |
| Rasmussen Reports | Asbury Park | 2003 |
| Raytheon Technologies Corporation | condado de Arlington | 3 de abril de 2020 |
| RC4WD | San Francisco | 2001 |
| RCA Records | Nueva York | 1901 |
| Realty income | San Diego | 1969 |
| Red Digital Cinema Camera Company | Lake Forest | 2005 |
| Red Orb Entertainment | Novato | 1997 |
| Redfin | Seattle | 2004 |
| Reebok | Boston | 1895 |
| Regeneron Pharmaceuticals | Eastview | 1988 |
| Regent Seven Seas Cruises | Miami | 1990 |
| Remington Arms | Madison | 1816 |
| Remo | Santa Clarita | 1957 |
| Remote Control Productions | Santa Mónica | 1989 |
| Replit | San Francisco | — |
| Revlon | Nueva York | 1932 |
| Richard Childress Racing | — | 1969 |
| Rickenbacker | Santa Ana | 1931 |
| RJR Nabisco | condado de Cobb, Winston-Salem, Nueva York | 25 de abril de 1986 |
| RKO Pictures | Manhattan | 23 de octubre de 1928 |
| Robinhood | Palo Alto | 2013 |
| Robinson Helicopter | Zamperini Field | 1973 |
| Roblox Corporation | San Mateo | 2004 |
| Rocketdyne | Los Ángeles | 1955 |
| Rogers Locomotive and Machine Works | — | 1832 |
| Roku, Inc | Los Gatos | octubre 2002 |
| Room to Read | San Francisco | 2000 |
| Roxio | Santa Clara | 2001 |
| Royal Caribbean Group | Miami | 1997 |
| RR Donnelley | Chicago | 1864 |
| RSA Security | Bedford | 1986 |
| Saatchi & Saatchi | Nueva York | 1970 |
| Safeway | Pleasanton | 1915 |
| Saks Fifth Avenue | Nueva York | 1898 |