# M4

M4 or M-4 most often refers to:
* M4 carbine, an American carbine
* M4 Sherman, an American World War II medium tank
M4, M04, or M-4 may also refer to:

## Arts and entertainment

* M4 (EP), a 2006 EP by Faunts
* M4 (video game), a 1992 computer game developed for the Macintosh
* M.IV ("Matrix IV"), the fictional Warner Brothers videogame project inside the 2021 film The Matrix Resurrections
* Former name of band First to Eleven
* M4, the robot assistant to the character Flint in the Star Trek episode Requiem for Methuselah

## Military
### Weapons

* Benelli M4 Super 90, an Italian semi-automatic,gas-operated shotgun
* M4 autocannon, an American 37 mm automatic gun
* M4 Selectable Lightweight Attack Munition (SLAM), an American land mine
* M4 SLBM, a French submarine-launched ballistic missile from 1985
* M4 Survival Rifle, an American rifle in aircraft survival gear
* Spectre M4, an Italian submachine gun
* M4 bayonet, an American World War II bayonet used for the M1 Carbine
* Gross-Basenach M IV, a pre-WWI German military semi-rigid airship

### Aircraft, ships, and vehicles

* HSwMS Carlskrona (M04), a 1980 Swedish Navy minelayer, later redesignated as ocean patrol vessel P04
* HSwMS M4, a Swedish Navy mine sweeper
* HMS Roberts (1915) (M4), a First World War British Royal Navy monitor
* HMS M4 (1919), a British M-class submarine
* M4 tractor, a U.S. Army artillery tractor from 1943
* Myasishchev M-4, a 1950s Soviet strategic bomber aircraft
* Meusel M-IV, a German glider; see List of German gliders

### Other uses in military

* M4 flame fuel thickening compound, a substance used in fire bombs and incendiary weapons
* M4 (German Navy 4-rotor Enigma), a variant of the Enigma cryptography machine
* M04, desert variant of M05, a camouflage pattern used by the Finnish Defence Forces

## Science and technology
### Biology, medicine and organic chemistry

* ATC code M04, Antigout preparations, a subgroup of the Anatomical Therapeutic Chemical Classification System
* British NVC community M4, a type of mire plant community in the British National Vegetation Classification system
* M4, the FAB classification of acute myelomonocytic leukemia
* Muscarinic acetylcholine receptor M$_4$, a protein

### Computing and electronics

* Apple M4, a central processing unit in the Apple M series
* m4 (computer language), a macro processing language
* M4, part number for a 1N400x general purpose diode
* Sony Xperia M4 Aqua, a mobile phone
* ARM Cortex-M#Cortex-M4, a processor family

### Other uses in science and technology

* Messier 4 (M4), a globular cluster in the Scorpius constellation of stars
* Leica M4, a 1967 35 mm camera
* M4, an ISO metric screw thread
* Foton-M No.4, a Russian microgravity and bioscience research spacecraft launched in July 2014

## Transportation
### Air

* Covington Municipal Airport (Tennessee), FAA location identifier M04
* Maule M-4, a 1960 American four-seat cabin monoplane aircraft
* Miles M.4 Merlin, a 1930s British five-seat cabin monoplane aircraft

### Rail

* Bucharest Metro Line M4, Romania
* Line 4 (Budapest Metro), Metro 4 or M4, Hungary
* M4 (Copenhagen), a future expansion of the Copenhagen Metro, Denmark
* M4 (Istanbul Metro), a subway line on the Asian side of Istanbul, Turkey
* M4, variant of the M2, an American electric multiple unit on the Metro-North Railroad
* M4, an American rapid transit car on the Market–Frankford Line
* Milan Metro Line 4, rapid transit line in Milan, Italy
* Sri Lanka Railways M4, a class of diesel-electric locomotive
* M4 (Warsaw), proposed subway line in Warsaw, Poland

### Road

* BMW M4, a car
* M4 Vacamatic, a 1941 semi-automatic transmission made by Chrysler
* M4, a bus route of Fifth and Madison Avenues Line, New York City, U.S.
* Mid-engine, four-wheel-drive layout, or M4 layout, an automotive design
* List of M4 roads

## Other uses

* Héctor David Delgado Santiago (1975–2013, alias El Metro 4, sometimes M4), Mexican drug lord
* M4, a measure of money supply
* M4-, M4+ and M4x, disciplines in men's rowing
* MLBB M4 World Championship, the fourth esports world championship for the mobile game Mobile Legends: Bang Bang held in 2023
* M4, a difficulty grade in mixed climbing