E4, E.IV or E-4 may refer to:

Entertainment

* E4 (TV channel), a television channel in the United Kingdom and Ireland * ''

Every Extend Extra Extreme ''Every Extend Extra Extreme'' is a game for the Xbox 360's Xbox Live Arcade service released on October 17, 2007. It is an expanded version of the PlayStation Portable game ''Every Extend Extra'' which is, in itself, an expanded version of the 20 ...

'', a video game from Q Entertainment * Entertainment for All, a video game expo

Transportation

* Aero Asia International, an airline, by IATA code

Roads

* European route E4, a road through Finland and Sweden * E4 European long distance path, a European long-distance trail * Tōhoku Expressway, route E4 in Japan * E4 expressway (Pakistan) * South Kedah Expressway in Malaysia * Subic Freeport Expressway in the Philippines

Trains

* E4 Series Shinkansen, a Japanese high-speed train * CNW Class E-4, a 4-6-4 steam locomotive of the Chicago & Northwestern Railway * EMC E4, a diesel locomotive * LB&SCR E4 class, a steam locomotive of the London, Brighton & South Coast Railway * LNER E4 Class, a 2-4-0 steam locomotive built by the Great Eastern Railway and operated by the LNER

Military

* Boeing E-4, a U.S. military flying command post * Fokker E.IV, a 1915 German fighter aircraft * E4, the fourth enlisted rank in the Military of the United States, including: ** Petty officer third class in the United States Navy and United States Coast Guard ** Senior airman in the United States Air Force (

Sergeant Sergeant (Sgt) is a Military rank, rank in use by the armed forces of many countries. It is also a police rank in some police services. The alternative spelling, ''serjeant'', is used in The Rifles and in other units that draw their heritage f ...

until 1976) ** Specialist (rank) in the United States Army (if the soldier is not a non-commissioned officer) ** Corporal in the United States Army and United States Marine Corps (if the soldier is a non-commissioned officer)

Science and technology

* E4-isoprostane, a type of isoprostane * Leukotriene E4, a naturally produced eicosanoid lipid mediator * E-4 process, an obsolete development process associated with photographic transparency film * Honda E4, a predecessor of Honda's ASIMO robot * RCS-4, a synthetic cannabinoid sold as "E-4" * E4 or E₄, an old name for the exceptional group F₄ * Estetrol, an estrogen

Other uses

* E4, a postcode district in the E postcode area * King's Pawn Game, or 1. e4, a chess opening move * E4 grade, a grade of difficulty in rock climbing * E4 or E₄, musical notation indicating the E above Middle C