AC-4

AC-4 or AC4 may refer to:

Music

 * AC4 (band), a Swedish hardcore punk band, or their eponymous album

Aircraft

 * Light Wing AC4, an aircraft
 * Aviastroitel AC-4 Russia, glider
 * Comte AC-4, a two-seat Swiss monoplane

Ships

 * USS Cyclops (AC-4), a US Navy collier ship

Trains

 * Southern Pacific class AC-4, a class of steam locomotive

Tanks

 * AC4 tank a World War Two Australian cruiser tank.

Technology

 * AC-4, an IEC Utilization Category
 * Dolby AC-4, Dolby Digital audio codec

Videogames

 * Ace Combat 04: Shattered Skies, a 2001 video game
 * Armored Core 4, a 2006 video game
 * Assassin's Creed IV: Black Flag, a 2013 video game