| Da Capo Press | publishing house | Boston | 1964 |
| Dallas Semiconductor | business | Dallas | February 1, 1984 |
| Dallas Theological Seminary | private not-for-profit educational institution, seminary | — | 1924 |
| DallasNews Corporation | newspaper publisher, business, enterprise, company, public company | Dallas | 2008 |
| Dark Castle Entertainment | film production company | Los Angeles | 1999 |
| Dark Horse Entertainment | film production company | — | 1992 |
| Datadog | business, public company | New York City | 2010 |
| Datapoint | business | — | 1968 |
| DataStax | business | Santa Clara | April 2010 |
| Daybreak Game Company | video game developer | San Diego | 1995 |
| Dayton Art Institute | nonprofit organization, arts educational institution, art museum | Dayton | 1930 |
| DC Comics | comics publishing company, book publisher | Manhattan, Burbank | 1977 |
| DC Studios | film production company | Burbank | November 1, 2022 |
| DDB Worldwide | business | Chicago, San Francisco, London | 1949 |
| Dean Guitars | business, musical instrument manufacturing company | — | 1976 |
| Deep Space Industries | business, enterprise | Mountain View | January 22, 2013 |
| Deere & Company | business, enterprise, public company | Moline | 1868 |
| Defense Commissary Agency | supermarket chain, government agency | Fort Lee | October 1, 1991 |
| Delaware State University | historically black college or university, public educational institution of the United States, university, land-grant university | — | 1891 |
| Dell | business, enterprise, public company | Round Rock | September 7, 2016 |
| Dell Publishing | comics publishing company, publishing house | New York City | 1921 |
| Dell Technologies | business, enterprise, public company | Round Rock | September 7, 2016 |
| Delmark Records | record label, business, company | — | 1953 |
| Delmonico's | restaurant | — | December 13, 1827 |
| Delta State University | public educational institution of the United States, university | Cleveland | 1924 |
| DePauw University | liberal arts college, private not-for-profit educational institution | Greencastle | 1837 |
| Destination Films | film production company, film distributor | Culver City | 1999 |
| DeVry University | private university | — | 1931 |
| Diamond Multimedia | business | Los Angeles | 1982 |
| Diamond-Star Motors | business, automobile manufacturer | — | October 1985 |
| Dickies | business, enterprise, brick and mortar | Fort Worth | 1918 |
| Diebold Nixdorf | business, enterprise, public company | North Canton | 1859 |
| Digital Anvil | video game developer | Austin | 1996 |
| Digital Domain | public company | Playa Vista, Venice | 1993 |
| Digital Photography Review | website, business | — | 1998 |
| Digital Playground | pornographic film distributor, pornography company, pornographic film studio | Chatsworth, Van Nuys | 1993 |
| Digital Realty Trust | business, real estate investment trust, public company | Austin | 2004 |
| Dillard's | department store chain, public company | Little Rock | 1938 |
| Dimension Films | film production company | New York City | 1992 |
| Dimensional Fund Advisors | asset management company, business, enterprise | Austin | 1981 |
| Din Tai Fung | restaurant chain | Taipei | May 7, 1991 |
| Diners Club International | business, enterprise | Riverwoods | 1950 |
| Disney California Adventure | theme park | — | February 8, 2001 |
| Disney Cruise Line | business, cruise line | Celebration | 1995 |
| Disney D23 | fan club, website, business | Burbank | 2009 |
| Disney Interactive Studios | video game developer | Glendale | December 5, 1994 |
| Disney Music Group | record label, record company, business | Burbank | 1998 |
| Disney Streaming | business | New York City | August 13, 2015 |
| Disney Television Studios | television production company, division | — | May 15, 2019 |
| Disney's Hollywood Studios | theme park | — | May 1, 1989 |
| Disneyland Hotel | hotel | — | 1955 |
| Docusign | business, public company | San Francisco | 2003 |
| Dodd, Mead & Co. | publishing house | New York City | 1839 |
| Dodge | car brand, business, enterprise, automobile manufacturer | Dodge Building | December 14, 1900 |
| Dodge & Cox | business, enterprise | San Francisco | 1930 |
| Dollar Tree | business, retail chain, public company | Chesapeake | 1986 |
| Dominican University | private not-for-profit educational institution, university, Catholic university | — | 1901 |
| Dover Corporation | business, public company | Downers Grove | 1955 |
| Dow Chemical Company | organization, business, enterprise, public company | Midland | 1897 |
| Dow Inc. | enterprise, public company | Midland | January 1, 2019 |
| Dow Jones & Company | business, enterprise | New York City | 1882 |
| Dr Pepper Snapple Group | business, public company | Plano | May 7, 2008 |
| Dr. Scholl's | brand, business | Chicago, London | 1906 |
| Drag City | independent record label | Chicago | 1990 |
| Dremel | trademark, business | Racine | 1932 |
| Drum Workshop | business, musical instrument manufacturing company, enterprise | Oxnard | 1972 |
| Duke University Press | open-access publisher, university press | Durham | 1921 |
| Dumbarton Oaks | research library, mansion, research institute, museum, academic publisher | — | 1940 |
| Dun & Bradstreet | business, subsidiary company, enterprise | — | 1841 |
| Dunkin' | fast food restaurant chain, business | Canton, Quincy | 1950 |
| Dunkin' Brands | business, enterprise, public company | Canton | 1950 |
| Dunlop Manufacturing | business, enterprise | Benicia | 1965 |
| Durant Motors | automobile manufacturer | Lansing | 1921 |
| Dyn | business | Manchester | 1998 |
| Dynatrace | software company, public company | Boston | February 2, 2005 |