| R. J. Reynolds Tobacco Company | business, enterprise | Winston-Salem | 1874 |
| Radcliffe College | college | — | 1879 |
| Radford University | public educational institution of the United States, university | — | 1910 |
| Radio Free Asia | radio station, broadcaster, nonprofit organization, news agency | Washington, D.C. | 1994 |
| RadioShack | group of companies, electronics store chain, public company | Fort Worth | 1921 |
| Radisson Blu | hotel chain | Brussels metropolitan area | 1994 |
| Radisson Hotel Group | privately held company, hotel chain, business | Minnetonka | 1962 |
| Rainforest Cafe | restaurant chain, business | Houston | 1994 |
| Ram Trucks | car brand, division, automobile manufacturer | Auburn Hills | 2010 |
| Random House | publishing house | Random House Tower, New York City | 1927 |
| Rankin/Bass Animated Entertainment | television production company | New York City | September 14, 1960 |
| RatPac-Dune Entertainment | business, enterprise | Los Angeles | 2006 |
| Raven Software | video game developer | Middleton, Madison | 1990 |
| Ravn Alaska | regional airline | Anchorage | January 1, 2010 |
| Raytheon | defense contractor, public company | Waltham | July 7, 1922 |
| Razer Inc. | privately held company, business, public company | George Town, Singapore, Carlsbad, Irvine, San Francisco | 1998 |
| RCA Corporation | business | Rockefeller Center, New York City | 1919 |
| RE/MAX | brokerage firm, business, enterprise | Denver | 1973 |
| RealNetworks | privately held company, business, enterprise | Seattle | 1993 |
| Realty Income Corporation | real estate company, business, public company | San Diego | 1969 |
| Red Digital Cinema Camera Company | camera manufacturer, business, enterprise | Lake Forest | 2005 |
| Red Orb Entertainment | business | Novato | 1997 |
| Red Wing Shoes | business, enterprise, brick and mortar | Red Wing | 1905 |
| Reddit | user-generated content platform, art-sharing website, news aggregation website, social networking service, aggregator, social news website, online community | San Francisco | June 23, 2005 |
| Regeneron Pharmaceuticals | business, public company | Eastview | 1988 |
| Regent Seven Seas Cruises | business | Miami | 1990 |
| Regent University | law school, church college, private not-for-profit educational institution, university | — | 1978 |
| Regions Financial Corporation | business, enterprise, credit institution, public company | Birmingham | July 13, 1971 |
| Regis University | private not-for-profit educational institution, university, open-access publisher | Denver | 1877 |
| Relativity Media | film production company, film distributor | Beverly Hills | 2004 |
| Remington Rand | business | Buffalo, New York City | 1927 |
| Renegade Kid | video game publisher, video game developer | Austin | 2007 |
| Replit | business, online integrated development environment | San Francisco | — |
| Republic Aviation Corporation | aerospace manufacturer | Farmingdale | 1931 |
| Republic Pictures | Poverty Row | Hollywood | 1935 |
| Revell | manufacturer, business | Elk Grove Village | 1943 |
| ReverbNation | website, business | Durham | October 31, 2006 |
| Rhode Island School of Design | arts venue, design school, private not-for-profit educational institution, collection, private university | — | March 22, 1877 |
| Rice University | research university, private not-for-profit educational institution, private university | Houston | 1891 |
| Ring of Honor | business, enterprise, professional wrestling promotion | — | 2002 |
| Riseup | internet service provider, mailbox provider, collective, worker cooperative, charitable organization | Seattle | 1999 |
| Ritual Entertainment | video game developer | Dallas | 1996 |
| Roblox Corporation | video game developer, business, public company | San Mateo | 2004 |
| Rockhurst University | private not-for-profit educational institution, university | Clayton | 1910 |
| Rockstar Games | video game publisher | New York City | December 1998 |
| Rockstar New England | video game developer | Andover | 1999 |
| Rockwell Collins | defense contractor, business, public company, aerospace manufacturer | Cedar Rapids | 1933 |
| Rockwell International | conglomerate, public company | United States | February 1973 |
| Rogue | film production company | Universal City | 1997 |
| Roku, Inc. | business, enterprise, public company | Los Gatos | October 2002 |
| Rooster Teeth | YouTube channel, film production company | Austin, Los Angeles, Flower Mound | April 1, 2003 |
| Rowan University | public educational institution of the United States, public university | Glassboro | 1923 |
| Rowman & Littlefield | book publisher, publishing house | Lanham | 1949 |
| Roxy Theatre | nightclub, music venue | — | September 23, 1973 |
| Royal Caribbean Group | business, enterprise, public company | Miami | 1997 |
| Royal Hawaiian Hotel | hotel, hotel building | — | 1927 |
| Rutgers University Press | university press | New Brunswick | 1936 |
| Rutherford B. Hayes Presidential Center | library | — | 1912 |
| Ryder | business, retail chain, public company | Coral Gables | 1933 |