| D'Addario | business | Farmingdale | 1973 |
| Da Capo Press | publishing house | Boston | 1964 |
| Dag Hammarskjöld Library | library, library building | — | 1946 |
| Dairy Queen | fast food restaurant chain, restaurant chain, ice cream parlor chain | Bloomington, Edina | June 22, 1940 |
| Dallas Semiconductor | business | Dallas | February 1, 1984 |
| DallasNews Corporation | newspaper publisher, business, enterprise, company, public company | Dallas | 2008 |
| Dana Corporation | business, public company | Toledo | 1904 |
| Danaher Corporation | commercial organization, conglomerate, public company | Washington, D.C. | 1981 |
| Danjaq | business, enterprise, company | Santa Monica | 1962 |
| Darden Restaurants | business, enterprise, public company | Orange County | 1968 |
| Dark Castle Entertainment | film production company | Los Angeles | 1999 |
| Dark Horse Comics, LLC | comics publishing company, book publisher, publishing house | Milwaukie | February 4, 1986 |
| Databricks | software company, business | San Francisco | 2013 |
| Datadog | business, public company | New York City | 2010 |
| Datapoint | business | — | 1968 |
| DataStax | business | Santa Clara | April 2010 |
| Davidson College | private not-for-profit educational institution, liberal arts college in the United States | — | 1837 |
| Davis Entertainment | film production company | United States | 1984 |
| DC Comics | comics publishing company, book publisher | Manhattan, Burbank | 1977 |
| DC Universe | broadcaster, subscription, website, business, video streaming service, video on demand | Burbank | 2018 |
| Deck Nine | video game developer | Louisville | 1997 |
| Del Taco | fast food restaurant chain, public company | Lake Forest | 1965 |
| Dell | business, enterprise, public company | Round Rock | September 7, 2016 |
| Dell EMC | business, enterprise, public company | Hopkinton | August 1979 |
| Dell Technologies | business, enterprise, public company | Round Rock | September 7, 2016 |
| Delmonico's | restaurant | — | December 13, 1827 |
| DeLorean Motor Company | automobile manufacturer | Detroit | October 24, 1975 |
| Democratic National Committee | business | Washington, D.C. | 1848 |
| Denison University | liberal arts college, Colleges That Change Lives, private not-for-profit educational institution | — | 1831 |
| Denny's | restaurant chain, pancake house, public company | Spartanburg | 1953 |
| DePaul University | private not-for-profit educational institution, university | Chicago | 1898 |
| DePauw University | liberal arts college, private not-for-profit educational institution | Greencastle | 1837 |
| Desilu | television production company | Los Angeles | 1950 |
| Detroit Electric Car Company | business, automobile manufacturer | Detroit | 1907 |
| Detroit Institute of Arts | nonprofit organization, art museum, museum, performing arts center, movie theater | — | 1885 |
| Devil's Film | television production company, pornographic film distributor, pornographic film studio | Los Angeles | 1997 |
| Devon Energy | business, enterprise, public company | Oklahoma City | 1971 |
| DeVry University | private university | — | 1931 |
| DeWALT | brand, enterprise | Towson | 1924 |
| Diamond-Star Motors | business, automobile manufacturer | — | October 1985 |
| DIC Entertainment Corporation | television production company, animation studio, film production company | Burbank | 1971 |
| Dick's Sporting Goods | business, public company | Coraopolis | 1948 |
| Dickies | business, enterprise, brick and mortar | Fort Worth | 1918 |
| Digital Anvil | video game developer | Austin | 1996 |
| DigitalBridge | public company | Boca Raton | 1991 |
| DigitalOcean | computing platform, business, public company | New York City | August 2011 |
| Din Tai Fung | restaurant chain | Taipei | May 7, 1991 |
| Diners Club International | business, enterprise | Riverwoods | 1950 |
| Dischord Records | independent record label | Washington, D.C. | 1980 |
| Discover Financial | commercial organization, credit institution, public company | Wilmington, Riverwoods | 1960 |
| Discovery, Inc. | business, enterprise, public company | New York City | 1982 |
| Disney Cruise Line | business, cruise line | Celebration | 1995 |
| Disney Television Animation | business | Glendale | December 5, 1984 |
| Disney Television Studios | television production company, division | — | May 15, 2019 |
| DLA Piper | law firm | New York City | 2005 |
| Dolby | business, enterprise, public company | San Francisco | 1965 |
| Dollar General | variety store chain, discount store, business, retail chain, enterprise, public company | Goodlettsville | 1939 |
| Dominican University | private not-for-profit educational institution, university, Catholic university | — | 1901 |
| Dominion Energy | business, enterprise, public company | Richmond | 1983 |
| DoubleTree by Hilton | hotel brand, hotel chain, business, enterprise | McLean | 1969 |
| Dover Publications | book publisher, music publisher, public company | New York, Mineola | 1941 |
| Dow Inc. | enterprise, public company | Midland | January 1, 2019 |
| Dow Jones & Company | business, enterprise | New York City | 1882 |
| Drag City | independent record label | Chicago | 1990 |
| DreamWorks | film production company, film distributor | Universal City | October 12, 1994 |
| DreamWorks Animation | animation studio, film production company, film studio, public company | Glendale | 1994 |
| Drexel University | research university, private not-for-profit educational institution | — | 1891 |
| Dumbarton Oaks | research library, mansion, research institute, museum, academic publisher | — | 1940 |
| Dun & Bradstreet | business, subsidiary company, enterprise | — | 1841 |
| Dunkin' Brands | business, enterprise, public company | Canton | 1950 |
| Duquesne University | private not-for-profit educational institution, Catholic university | — | 1878 |
| Durant Motors | automobile manufacturer | Lansing | 1921 |
| DYMO Corporation | business | Berkeley | 1958 |
| Dynamite Entertainment | comics publishing company, production company, publishing house, imprint | Mount Laurel | 2004 |