| Perplexity AI | San Francisco | December 7, 2022 |
| Petco | San Diego | 1965 |
| PetSmart | Phoenix | 1986 |
| Philip Morris International | Stamford, Lausanne | 1987 |
| Phillips Petroleum Company | Bartlesville | 1917 |
| Pierce-Arrow | Buffalo | 1870 |
| PIMCO | Newport Beach | 1971 |
| Pinkberry | Los Angeles | 2005 |
| Pinnacle Systems | Mountain View | 1986 |
| Pioneer Hi-Bred | Johnston | 1926 |
| Planet Labs | San Francisco | December 28, 2010 |
| Playboy Enterprises | Los Angeles | 1953 |
| PNC Financial Services | One PNC Plaza | 1982 |
| PNY Technologies | Parsippany-Troy Hills | 1985 |
| Polycom | San Jose | 1990 |
| Powell Peralta | — | 1978 |
| Powell's Books | Portland | 1971 |
| Powerset | San Francisco | 2005 |
| PR Newswire | Manhattan | March 8, 1954 |
| Pratt & Whitney | East Hartford | 1925 |
| Precision Manuals Development Group | Alexandria | 1997 |
| Principal Financial Group | Des Moines | 1879 |
| Pro Wrestling Guerrilla | Southern California | 2003 |
| Proactiv Solution | — | 1995 |
| Providence Equity Partners | 50 Kennedy Plaza | 1989 |
| Pyra Labs | San Francisco | 1999 |
| Quaker Oats Company | Chicago | 1877 |
| Qualcomm | San Diego | July 1985 |
| Qualtrics | Provo | 2002 |
| Quiksilver | Huntington Beach | 1969 |
| Quora | Mountain View | June 21, 2010 |
| QVC | Düsseldorf | 1986 |
| Rawlings | Town and Country | 1887 |
| RCA Corporation | Rockefeller Center, New York City | 1919 |
| RCA Records | New York City | 1901 |
| Real3D | Orlando | 1986 |
| RealNetworks | Seattle | 1993 |
| Redfin | Seattle | 2004 |
| Regent Seven Seas Cruises | Miami | 1990 |
| Remo | Santa Clarita | 1957 |
| Remote Control Productions | Santa Monica | 1989 |
| REO Motor Car Company | Lansing | 1905 |
| Replit | San Francisco | — |
| ReverbNation | Durham | October 31, 2006 |
| Revlon | New York City | 1932 |
| Reynolds American | Winston-Salem | 2004 |
| Richard Childress Racing | — | 1969 |
| Ring Ka King | Pune | 2011 |