G4 or G.IV may refer to:

Places

County Route G4 (California) There are 21 routes assigned to the "G" zone of the California Route Marker Program, which designates county routes in California. The "G" zone includes county highways in Monterey County, California, Monterey, San Benito County, California, Sa ...

, a county highway in Santa Clara County, California, USA *

G4 Beijing–Hong Kong and Macau Expressway The Beijing–Hong Kong and Macau Expressway (), designated as G4 and commonly referred to as the Jinggang'ao Expressway () is a -long expressway that connects the Chinese cities of Beijing and Shenzhen, in Guangdong province, at the border of ...

, an expressway in China * G4 (Taichung Metro), also known as Songzhu Station or Jiushe Station, a station under construction in the Taichung Metro

Arts, entertainment, games, media

G4 (American TV network) G4 (also known as G4TV) was an American pay television and digital network owned by NBCUniversal and later Comcast Spectacor that primarily focused on video games. The network was originally owned by G4 Media (TV company), G4 Media, a joint v ...

, an American television channel * G4 (Canadian TV channel), a former Canadian television channel * G4 (group), a British vocal troupe * Grob's attack, an opening move in chess

Groups, organisations, companies

* G4 nations, four nations that support each other's bids to become permanent members of the United Nations Security Council: Brazil, Germany, India, and Japan * Big Four (Western Europe), sometimes called 'G4', a group of powerful countries in Europe * VIP Protection Unit, a unit of the Hong Kong Police Force (originally Section G, Division 4) * Allegiant Air, by IATA airline designator

Electrics, electronics, and computing

* G4, a type of bi-pin lamp base (socket), a lamp fitting where the pin spacing is 4mm * LG G4 smartphone * Moto G4, a line of smartphones * Group 4 compression, a type of image compression used in fax machines and some image file formats

Apple Computer

* PowerPC G4, a type of microprocessor by Freescale used by Apple ** Power Mac G4, a series of personal computers made by Apple Inc in July 1999 ** PowerBook G4, a series of Professional notebooks made by Apple Inc in 2001 ** iMac G4, a series of personal computer made by Apple Inc in January 2002 ** Xserve G4, an Xserve#Xserve G4, Xserve server made by Apple Inc in May 2002 ** iBook G4, an iBook#iBook G4, iBook series of consumer notebooks in October 2003 ** Mac Mini G4, a Mac Mini#First generation (G4 Polycarbonate), Mac Mini series of ultracompact computer in January 2005

Science and medicine

* G-4 (Ganesha-4), an amphetamine psychoactive drug and derivative of the psychedelic Ganesha (psychedelic)#G-4, Ganesha

Vehicles

* AEG G.IV, a German World War I heavy bomber * Caudron G.4, a 1915 French biplane * Friedrichshafen G.IV, a 1918 German medium bomber * Gotha G.IV, a 1916 German heavy bomber * Gulfstream IV, a family of private jet aircraft * Mitsubishi G4M "Betty", a World War II Japanese fast bomber * Soko G-4 Super Galeb, a jet trainer/light attack jet of Yugoslav origin * USS G-4 (SS-26), USS ''G4'' (SS-26), a 1914 G-class submarine of the United States Navy * G4-class freighter, a cargo ship design * LNER Class G4, a class of British steam locomotives * Pontiac G4, a compact car sold in Mexico

Other uses

* G4 EA H1N1, a strain of influenza * G-quadruplex, a DNA secondary structure * Group 4 element, a class of elements on the Periodic Table * ATC code G04 ''Urologicals'', a subgroup of the Anatomical Therapeutic Chemical Classification System * Galactic 04 (G04), a Virgin Galactic suborbital tourist spaceflight in October 2023, the first spaceflight of a Pakistani