| U.S. Bancorp | business, financial institution, credit institution, public company | Minneapolis | 1850 |
| U.S. Steel | business, enterprise, public company | Pittsburgh | 2001 |
| Udacity | educational institution, website, company | Mountain View | June 2011 |
| Udemy | website, education company | San Francisco | 2010 |
| UL LLC | standards organization, certification services provider, partnership | Northbrook | 1894 |
| Ultimate Fighting Championship | mixed martial arts organization, enterprise | Nevada, Las Vegas | 1993 |
| Undead Labs | business | Seattle | November 23, 2009 |
| Unimation | business | — | 1962 |
| Union Carbide | business, enterprise | Danbury | 1957 |
| Union College | private not-for-profit educational institution, private university | Schenectady | February 25, 1795 |
| Union Iron Works | business | San Francisco | 1849 |
| Union Pacific Railroad | railway company, public company | Omaha | 1862 |
| United Airlines | holding company, airline, public company | Chicago, Willis Tower | April 6, 1926 |
| United Airlines Holdings | business, enterprise, public company | Chicago | December 30, 1968 |
| United Fruit Company | multinational corporation, business | New Orleans | 1899 |
| United Parcel Service | business, public company | Sandy Springs | August 28, 1907 |
| United Plankton Pictures | privately held company | Burbank | April 1, 1998 |
| United Press International | news agency, organization, business, enterprise | Washington, D.C. | 1907 |
| United Space Alliance | business, enterprise | Houston | August 1995 |
| United States Air Force Academy | Field Operating Agency, air force academy | Air Force Academy | August 14, 1954 |
| United States Army Command and General Staff College | staff college | Fort Leavenworth | 1881 |
| United States Army Infantry School | military infantry school | Fort Benning | 1918 |
| United States Army War College | Direct Reporting Unit, staff college, military school | — | 1901 |
| United States Centers for Disease Control and Prevention | United States federal agency, open-access publisher | Atlanta | — |
| United States Coast Guard Academy | military school, public educational institution of the United States, coast guard academy, military academy | New London | 1876 |
| United States Government Publishing Office | legislative branch agency, state publisher | — | 1861 |
| United States Military Academy | Direct Reporting Unit, public educational institution of the United States, military museum, military academy | — | March 16, 1802 |
| United States Naval Academy | naval academy, public educational institution of the United States, census-designated place in the United States, observatory | Naval Academy | 1845 |
| United States Naval Institute | institute, 501(c)(3) organization, publishing house | Annapolis | 1873 |
| United States Playing Card Company | publishing house, business | Erlanger | 1867 |
| United States Rubber Company | business | Naugatuck | 1892 |
| United States Wrestling Association | business | Memphis | 1989 |
| United Technologies Corporation | business, enterprise, public company | Hartford | 1929 |
| UnitedHealth Group | business, enterprise, public company | Minnetonka | 1977 |
| Universal Epic Universe | theme park | — | May 22, 2025 |
| Universal Music Group | record label group, major label, record company, public company | Broadway, New York, Santa Monica, California | September 1934 |
| Universal Pictures | film production company, film studio | Universal City | April 30, 1912 |
| Universal Studios Florida | theme park | — | 1990 |
| Universal Studios Hollywood | theme park | — | 1964 |
| Universal Studios Home Entertainment | media distributor | Universal City | 1979 |
| University at Buffalo | public educational institution of the United States, open-access publisher, census-designated place in the United States, public research university | Amherst | 1846 |
| University of Alabama | public educational institution of the United States, public university | Tuscaloosa | 1831 |
| University of Alabama at Birmingham | public educational institution of the United States, public research university | — | 1969 |
| University of Alabama in Huntsville | public educational institution of the United States, university | — | 1950 |
| University of Alaska Fairbanks | public educational institution of the United States, land-grant university, public university | College | 1917 |
| University of Alaska System | state university system | Fairbanks | 1917 |
| University of Arkansas | public educational institution of the United States, land-grant university, public research university | Fayetteville | 1871 |
| University of Arkansas for Medical Sciences | medical university, public educational institution of the United States | — | 1879 |
| University of Austin | private not-for-profit educational institution, university | — | — |
| University of Baltimore | public educational institution of the United States, public university | Baltimore | 1925 |
| University of California College of the Law, San Francisco | law school, public educational institution of the United States, university, academic publisher | — | 1878 |
| University of California, Berkeley School of Law | law school | — | 1894 |
| University of California, Los Angeles | public educational institution of the United States, public research university | Los Angeles | May 23, 1919 |
| University of California, San Diego | public educational institution of the United States, public university | — | November 18, 1960 |
| University of Central Missouri | public educational institution of the United States, university | — | 1871 |
| University of Chicago Press | book publisher, university press | Chicago | 1891 |
| University of Cincinnati | public educational institution of the United States, public research university | — | 1819 |
| University of Colorado | university | Denver | 1876 |
| University of Colorado Colorado Springs | public educational institution of the United States, university | — | 1965 |
| University of Georgia | university | Old North Campus | 1785 |
| University of Hawaii Press | open-access publisher, university press | Honolulu | 1947 |
| University of Hawaiʻi at Hilo | public educational institution of the United States, university | — | 1941 |
| University of Hawaiʻi at Mānoa | public educational institution of the United States, land-grant university, public university | — | 1907 |
| University of Hawaiʻi–West Oʻahu | public educational institution of the United States, university | Kapolei | 1976 |
| University of Illinois Chicago | public educational institution of the United States, open-access publisher, public university | — | January 1983 |
| University of Illinois Press | book publisher, university press | Champaign | 1918 |
| University of Illinois Springfield | public educational institution of the United States, university | — | 1969 |
| University of Illinois Urbana-Champaign | public educational institution of the United States, land-grant university, public research university | — | 1867 |
| University of Kentucky | public educational institution of the United States, open-access publisher, land-grant university, public university | Lexington | 1865 |
| University of Louisiana at Monroe | public educational institution of the United States, university | — | 1931 |
| University of Louisville | public educational institution of the United States, public research university | Louisville | 1798 |
| University of Maryland | publishing house, public educational institution of the United States, land-grant university, public research university | College Park | 1856 |
| University of Maryland, Baltimore County | research university, public educational institution of the United States, university | — | 1966 |
| University of Massachusetts Amherst | public educational institution of the United States, university, land-grant university | Amherst | 1863 |
| University of Massachusetts Boston | public educational institution of the United States, university | Dorchester | 1964 |
| University of Memphis | public educational institution of the United States, public research university | — | 1912 |
| University of Miami | private not-for-profit educational institution, university | Coral Gables | 1925 |
| University of Michigan Law School | law school | — | 1859 |
| University of Michigan Press | open-access publisher, university press | Ann Arbor | 1930 |
| University of Minnesota Press | publishing house, university press | Minneapolis | 1925 |
| University of Missouri–Kansas City | public educational institution of the United States, public university | — | 1933 |
| University of Montana | research university, public educational institution of the United States, public university | — | 1893 |
| University of Nebraska Omaha | public educational institution of the United States, public university | — | 1908 |
| University of Nebraska system | state university system | Lincoln | 1850 |
| University of Nevada, Las Vegas | public educational institution of the United States, public research university | Las Vegas | September 10, 1957 |
| University of Nevada, Reno | public educational institution of the United States, land-grant university, public research university | Reno | 1874 |
| University of New Mexico | public educational institution of the United States, open-access publisher, public research university | Albuquerque | 1889 |
| University of North Carolina | state university system, state agency of North Carolina, educational institution | Chapel Hill | 1789 |
| University of North Carolina at Asheville | liberal arts college, public educational institution of the United States | Asheville | 1927 |
| University of North Carolina at Chapel Hill | public educational institution of the United States, public research university | — | December 11, 1789 |
| University of North Carolina Press | nonprofit organization, open-access publisher, university press | Chapel Hill | 1922 |
| University of North Dakota | research university, public educational institution of the United States, public university | — | 1883 |
| University of North Florida | public educational institution of the United States, university | — | 1969 |
| University of Notre Dame | private not-for-profit educational institution, open-access publisher, Catholic university, private university, academic publisher | — | November 26, 1842 |
| University of Oregon | research university, public educational institution of the United States, public university | Eugene | 1876 |
| University of Pennsylvania | colonial colleges, research university, private not-for-profit educational institution, private university | Philadelphia | November 14, 1740 |
| University of Puerto Rico | public university | — | 1903 |
| University of Rhode Island | research university, public educational institution of the United States, open-access publisher, land-grant university, public university | Kingston | 1892 |
| University of Saint Joseph | private not-for-profit educational institution, university | — | 1932 |
| University of San Diego | private not-for-profit educational institution, private university | San Diego | 1949 |
| University of South Carolina | research university, public educational institution of the United States, public university | — | 1801 |
| University of Tampa | private not-for-profit educational institution, university | — | 1931 |
| University of Tennessee | neighborhood, research university, public educational institution of the United States, university, land-grant university, sun grant institution, public university | Knoxville | 1794 |
| University of Tennessee at Chattanooga | public educational institution of the United States, public university | — | 1886 |
| University of Texas at Austin | public educational institution of the United States, public research university | Austin | 1883 |
| University of Texas Medical Branch | hospital, public educational institution of the United States, research institute, medical school | — | 1891 |
| University of Texas Press | university press | Austin | 1950 |
| University of Texas Southwestern Medical Center | public educational institution of the United States, medical organization, medical school | — | 1943 |
| University of Texas System | state university system | Austin | 1876 |
| University of the Incarnate Word | private not-for-profit educational institution, university | — | 1881 |
| University of Tulsa | private not-for-profit educational institution, university, academic publisher | — | 1894 |
| University of Vermont | public educational institution of the United States, open-access publisher, land-grant university, public research university | Burlington | 1791 |
| University of Virginia | public educational institution of the United States, public research university | Charlottesville | January 25, 1819 |
| University of Virginia School of Law | law school, faculty | — | 1819 |
| University of West Georgia | public educational institution of the United States, university | — | 1906 |
| University of Wisconsin Press | university press | Madison | 1936 |
| University of Wisconsin System | state university system | Madison | 1848 |
| University of Wisconsin–Green Bay | public university | — | 1965 |
| University of Wisconsin–La Crosse | public educational institution of the United States, public university | — | 1909 |
| University of Wisconsin–Madison | public educational institution of the United States, land-grant university, public research university | — | 1848 |
| University of Wisconsin–Milwaukee | research university, public educational institution of the United States, public university | Milwaukee | 1885 |
| University of Wisconsin–Stevens Point | public educational institution of the United States, university, public university | Stevens Point | 1894 |
| University of Wyoming | public educational institution of the United States, land-grant university, public university | — | March 1886 |
| University System of Maryland | state university system | Baltimore | 1988 |
| UPA | film production company | Burbank | 1944 |
| UPS Airlines | cargo airline | Louisville | 1988 |
| US Airways | airline | Tempe | 1937 |
| US Airways Express | airline | Tempe | 1967 |
| US Foods | business, public company | Rosemont | August 1, 1989 |
| USA Today Co. | business, enterprise | Tysons, New York City | October 6, 1906 |
| USAA | insurance company, bank, business, financial institution | — | 1922 |
| USC School of Cinematic Arts | faculty, film school | — | 1929 |
| Ushahidi Inc. | nonprofit organization, technology company | Nairobi | January 9, 2008 |