| Gab | dot-com company, social networking service, online community | Austin | August 15, 2016 |
| Gale | publishing house | Detroit, Farmington Hills | 1954 |
| Gallaudet University | private not-for-profit educational institution, university | Washington, D.C. | 1857 |
| Galoob | publishing house, business | South San Francisco | 1957 |
| Gap Inc. | business, enterprise, clothing store chain, public company | San Francisco | 1969 |
| GE Aerospace | business, aerospace manufacturer | Evendale | April 15, 1892 |
| GE HealthCare | business, medical device company, enterprise | Chicago | 2004 |
| GE Transportation | business, enterprise | Chicago, Heller International Building | 1907 |
| General Atomics | business, enterprise | San Diego | 1955 |
| General Mills | multinational corporation, public company | Golden Valley | 1866 |
| Genesys | business, enterprise | Daly City | 1990 |
| Gensler | architectural firm, business | San Francisco | 1965 |
| Genzyme | business, subsidiary company, enterprise | Cambridge | 1981 |
| GeoEye | business, defunct organization, company | Herndon | 1992 |
| George Bush Presidential Library | museum, library | — | 1997 |
| George Eastman Museum | film museum, photo library, nonprofit organization, photography museum, museum, film archive | Rochester | 1905 |
| George W. Bush Presidential Center | Presidential libraries system, nonprofit organization, museum | Dallas | 2013 |
| George Washington Birthplace National Monument | plantation, National Park System unit, national monument, National Monument of the United States | — | January 23, 1930 |
| Georgetown University | research university, private not-for-profit educational institution, Catholic university, private university | Washington, D.C. | January 23, 1789 |
| Georgia Southern University | public educational institution of the United States, university, open-access publisher | — | 1906 |
| Georgia Southern University-Armstrong Campus | public educational institution of the United States, university | — | 1935 |
| Georgia-Pacific | privately held company, business, enterprise, public company | Atlanta, Georgia-Pacific Tower | 1927 |
| Gerber Legendary Blades | organization, business | Tigard | 1939 |
| Gerber Products Company | business, subsidiary company | Fremont | 1927 |
| Getty Images | joint-stock company, photo archive, photo agency, public company | Seattle | 1995 |
| Getty Oil | business, gas station chain | East Meadow | 1964 |
| Ghirardelli Chocolate Company | chocolaterie | San Leandro | 1852 |
| Giant Sparrow | video game developer, business, enterprise | Santa Monica | March 22, 2009 |
| Gibson Brands | business, musical instrument manufacturing company | Tennessee, Nashville | 1902 |
| Glenn L. Martin Company | aerospace manufacturer | Baltimore | 1912 |
| Global Payments | business, public company | Atlanta | 2000 |
| GlobalFoundries | business, enterprise, public company | Malta | October 7, 2008 |
| Globalstar | telecommunications company | Covington | 1998 |
| GMT Games | board game publishing company, business, enterprise | Hanford | 1990 |
| Godiva Chocolatier | chocolaterie | New York City | 1926 |
| GoFundMe | crowdfunding platform, enterprise | — | 2010 |
| Golden Boy Promotions | business, enterprise | Los Angeles | 2002 |
| Golden Gate University | private not-for-profit educational institution, university | — | 1901 |
| Goldwyn Pictures | film production company | Hollywood | 1916 |
| Gonzaga University | Jesuit university, private not-for-profit educational institution | Spokane | 1887 |
| Goodyear Tire and Rubber Company | multinational corporation, business, enterprise, public company | Akron | August 29, 1898 |
| Google Arts & Culture | 3D computer graphics, video game developer, collection, website, software | — | February 2011 |
| Google Books | bibliographic database, digital library | — | 2005 |
| Google Nest | business | Palo Alto | 2010 |
| Goose Island Brewery | brewery | Chicago | 1988 |
| Governors State University | public educational institution of the United States, university | — | 1969 |
| Graflex | business | Rochester | 1889 |
| Graham Holdings Company | business, public company | Washington, D.C. | 1889 |
| Gramercy Pictures | film production company, film distributor | Universal City, Los Angeles | 2015 |
| Great Lakes Airlines | airline | Cheyenne | 1977 |
| Greenwood Publishing Group | book publisher | Santa Barbara | 1967 |
| Gretsch | trademark, musical instrument manufacturing company | New York City | 1883 |
| Greyhound Lines | intercity bus company, business | One Dallas Center | 1914 |
| Griptonite Games | video game developer | Kirkland | 1994 |
| Grossman School of Medicine | faculty, organization, medical school | New York City | 1841 |
| Groupon | business, public company | Chicago | 2008 |
| Grubhub | food delivery, online service, business, subsidiary company, enterprise | Chicago | 2004 |
| GTE | business, enterprise | Stamford | 1918 |
| Guardian Industries | business | Auburn Hills | 1932 |
| Guild Guitar Company | business, factory | Oxnard | 1952 |