| GameStop | business, retail chain, enterprise, brick and mortar, public company | Grapevine | August 20, 1980 |
| GameTek | video game publisher, business | North Miami Beach | 1987 |
| Gary Sanchez Productions | television production company, film production company | United States | — |
| GE Aerospace | business, aerospace manufacturer | Evendale | April 15, 1892 |
| GE Transportation | business, enterprise | Chicago, Heller International Building | 1907 |
| General American Transportation Corporation | business, enterprise, public company | Chicago | 1933 |
| General Atomics | business, enterprise | San Diego | 1955 |
| General Dynamics | business, public company | Reston | February 21, 1952 |
| General Dynamics Electric Boat | business, subsidiary company | Groton | 1899 |
| General Mills | multinational corporation, public company | Golden Valley | 1866 |
| General Tire | business | Fort Mill | 1915 |
| Gensler | architectural firm, business | San Francisco | 1965 |
| Genzyme | business, subsidiary company, enterprise | Cambridge | 1981 |
| GeoEye | business, defunct organization, company | Herndon | 1992 |
| Geological Society of America | nonprofit organization, publishing house, open-access publisher, learned society | Boulder | 1888 |
| George Mason University | public educational institution of the United States, university | Fairfax County | 1957 |
| Georgia State University | public educational institution of the United States, set, open-access publisher, public research university | Atlanta | 1913 |
| Gerber Legendary Blades | organization, business | Tigard | 1939 |
| 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 |
| GitHub | crowdsourced project, repository hosting service, repository web interface, issue tracking system, service on Internet, code reviewing software, continuous integration software, technology company, web application, forge, social networking service, website +4 | San Francisco | October 19, 2007 |
| GlassBridge Enterprises | business, enterprise, public company | Oakdale | 1996 |
| Glassdoor | review site, computing platform, business, employment website | Austin, San Francisco, Mill Valley | June 2007 |
| Glenn L. Martin Company | aerospace manufacturer | Baltimore | 1912 |
| Global Electric Motorcars | business, automobile manufacturer | Fargo | 1992 |
| Global Force Wrestling | professional wrestling promotion | Nashville | 2014 |
| Global Infrastructure Partners | investment fund, business | New York City | May 2006 |
| Gloria Jean's Coffees | business, café chain | Castle Hill | 1979 |
| Glu Mobile | video game publisher, video game developer, business, enterprise, public company | San Francisco | 2005 |
| GoDaddy | domain name registrar, payment processor, business, public company | Tempe | 1997 |
| GoJet Airlines LLC | airline | Bridgeton | 2004 |
| Golden Boy Promotions | business, enterprise | Los Angeles | 2002 |
| Golden Gate University | private not-for-profit educational institution, university | — | 1901 |
| Golden Nugget Las Vegas Hotel & Casino | skyscraper, casino, hotel | — | 1946 |
| Goodrich Corporation | business, enterprise | Charlotte | 1870 |
| 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 Fiber | network service provider | — | February 10, 2010 |
| Goose Island Brewery | brewery | Chicago | 1988 |
| GoTo | software company, enterprise, public company | Boston | 2003 |
| Governors State University | public educational institution of the United States, university | — | 1969 |
| Gracie Films | television production company, film production company | Culver City | 1987 |
| Graflex | business | Rochester | 1889 |
| Grand Valley State University | public educational institution of the United States, university | Allendale | 1960 |
| Grauman's Chinese Theatre | movie theater | — | May 18, 1927 |
| Gray Matter Interactive | video game developer | Los Angeles | 1994 |
| Gremlin Industries | business | San Diego | 1973 |
| Greyhound Lines | intercity bus company, business | One Dallas Center | 1914 |
| Groq | enterprise | Mountain View | 2016 |
| Guardian Industries | business | Auburn Hills | 1932 |
| Guggenheim Partners | business | Chicago | 1999 |
| Gulf and Western Industries | conglomerate | New York City | 1934 |